How To Become A Desktop Engineer
Interview Questions
===================
A) Tell me something about yourself.
Tell about your eductaion, place you belong to, some struggle in life which shows that you have positive attitude and will to fight the odds.
B) Technical Questions:
1) What is Active Directory?
A central component of the Windows platform, Active Directory directory service provides the means to manage the identities and relationships that make up network environments. For example we can create, manage and administor users, computers and printers in the network from active directory.
2) What is DNS? Why it is used? What is "forward lookup" and "reverse lookup" in DNS? What are A records and mx records?
DNS is domain naming service and is used for resolving names to IP address and IP addresses to names. The computer understands only numbers while we can easily remember names. So to make it easier for us what we do is we assign names to computers and websites. When we use these names (Like yahoo.com) the computer uses DNS to convert to IP address (number) and it executes our request.
Forward lookup: Converting names to IP address is called forward lookup.
Reverse lookup: Resolving IP address to names is called reverse lookup.
'A' record: Its called host record and it has the mapping of a name to IP address. This is the record in DNS with the help of which DNS can find out the IP address of a name.
'MX' Record: its called mail exchanger record. Its the record needed to locate the mail servers in the network. This record is also found in DNS.
3) What id DHCP? Why it is used? What are scopes and super scopes?
DHCP: Dynamic host configuration protocol. Its used to allocate IP addresses to large number of PCs in a network environment. This makes the IP management very easy.
Scope: Scope contains IP address like subnet mask, gateway IP, DNS server IP and exclusion range which a client can use to communicate with the other PCs in the network.
Superscope: When we combine two or more scopes together its called super scope.
4) What are the types of LAN cables used? What is a cross cable?
Types of LAN cables that are in use are "Cat 5" and "Cat 6". "Cat 5" can support 100 Mbps of speed and "CAT 6" can support 1Gbps of speed.
Cross cable: Its used to connect same type of devices without using a switch/hub so that they can communicate.
5) What is the difference between a normal LAN cable and cross cable? What could be the maximum length of the LAN cable?
The way the paired wires are connected to the connector (RJ45) is different in cross cable and normal LAN cable.
The theoritical length is 100 meters but after 80 meters you may see drop in speed due to loss of signal.
6) What would you use to connect two computers without using switches? Cross cable. 7) What is IPCONFIG command? Why it is used?
IPCONFIG command is used to display the IP information assigned to a computer. Fromthe output we can find out the IP address, DNS IP address, gateway IP address assigned to that computer.
8) What is APIPA IP address? Or what IP address is assigned to the computer when the DHCP server is not available?
When DHCP server is not available the Windows client computer assignes an automatic IP address to itself so that it can communicate with the network cmputers. This ip address is called APIPA. ITs in the range of 169.254.X.X.
APIPA stands for Automatic private IP addressing. Its in the range of 169.254.X.X.
9) What is a DOMAIN? What is the difference between a domain and a workgroup? Domain is created when we install Active Directory. It's a security boundary which is used to manage computers inside the boundary. Domain can be used to centrally administor computers and we can govern them using common policies called group policies.
We can't do the same with workgroup.
10) Do you know how to configure outlook 2000 and outlook 2003 for a user?
Please visit the link below to find out how to configure outlook 2000 and outlook 2003.http://www.it.cmich.edu/quickguides/qg_outlook2003_server.asp
11) What is a PST file and what is the difference between a PST file and OST file? What file is used by outlook express?
PST file is used to store the mails locally when using outlook 2000 or 2003. OST file is used when we use outlook in cached exchanged mode. Outlook express useds odb file.
12) What is BSOD? What do you do when you get blue screen in a computer? How do you troubleshoot it?
BSOD stands for blue screen of Death. when there is a hardware or OS fault due to which the windows OS can run it give a blue screen with a code. Best way to resolve it is to boot the computer is "LAst known good configuration". If this doesn't work than boot the computer in safe mode. If it boots up than the problemis with one of the devices or drivers.
13) What is RIS? What is Imaging/ghosting?
RIS stands for remote installation services. You save the installed image on a windows server and then we use RIS to install the configured on in the new hardware. We can use it to deploy both server and client OS. Imaging or ghosting also does the same job of capturing an installed image and then install it on a new hardware when there is a need. We go for RIS or iamging/ghosting because installing OS everytime using a CD can be a very time consuming task. So to save that time we can go for RIS/Ghosting/imaging.
14) What is VPN and how to configure it?
VPN stands for Virtual private network. VPN is used to connect to the corporate network to access the resources like mail and files in the LAN. VPN can be configured using the stepsmentioned in the KB: http://support.microsoft.com/kb/305550
15) Your computer slowly drops out of network. A reboot of the computer fixes the problem. What to do to resolve this issue?
Update the network card driver.
16) Your system is infected with Virus? How to recover the data?
Install another system. Insall the OS with the lates pathces, Antivirus with latest updates. Connect the infected HDD as secondary drive in the system. Once done scan and clean the secondary HDD. Once done copy the files to the new system.
17) How to join a system to the domain? What type of user can add a system to the domain?
Please visit the article below and read "Adding the Workstation to the Domain"
http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/directory/activedirectory/stepbystep/domxppro.mspx
18) What is the difference between a switch and a hub?
Switch sends the traffic to the port to which its meant for. Hub sends the traffic to all the ports.
19) What is a router? Why we use it?
Router is a switch which uses routing protocols to process and send the traffic. It also receives the traffic and sends it across but it uses the routing protocols to do so.
20) What are manageable and non manageable switches?
Switches which can be administered are calledmanageable switches. For example we can create VLAN for on such switch. On no manageable swiches we can't do so.
Microsoft outlook and Outlook express
Outlook Express is primarily an email client and newsgroup reader. It is the default email client supplied with Windows and comes free with Windows. It has all the basic facilities you expect from an email client - multiple identities, creation of folders to categories stored emails, and automated log-in and log-out. But it is just an email client.
Outlook is a full-blown contact management system. It enables you to store details on all your contacts, and to easily search and retrieve this data. It is NOT free with Windows, it is purchased as part of the Microsoft Office suite of programs. It uses the basic Outlook Express email engine as a part of its functionality. Overall it is much more powerful than the Express version. It is the sort of program a company would use to track its business contacts and their details for example. The average home user on the other hand is only likely to need to use Outlook Express, as the extra features in Outlook are all business orientated. A home user is notliekly to categories their friends for example, but a business will categories their contacts. Outlook will store electronic business cards, while Express cannot.
IT Helpdesk Questions
Technical Questions
1. What is NIC?
A network card, network adapter or NIC (network interface controller) is a piece of computer hardware designed to allow computers to communicate over a computer network
2. What is USB?
Universal Serial Bus (USB) is a serial bus standard to interface devices. Devices like Modem, Mouse, Keyboard etc can be connected.
3. Dialup vs. Broadband
A broadband connection (ADSL) provides high-speed Internet access over a standard phone line. The advantage of a broadband connection over a standard dialup service, is that Broadband is considerably faster, and is "always-on", meaning that once you"re logged on, your PC is online until the PC is turned off again.
Broadband offer high-speed Internet access and allows telephone calls and a permanent Internet connection to share a single phone line simultaneously whereas in Dialup connection either Internet connection or telephone call can made at given time.
4. LAN and WAN
A local area network is a computer network covering a small geographic area, like a home, office, or group of buildings
Wide Area Network (WAN) is a computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries). Or, less formally, a network that uses routers and public communications links
5. Microsoft Access
Microsoft Office Access, previously known as Microsoft Access, is a relational database management system from Microsoft.
6. What is RAS?
Remote Access Services (RAS) refers to any combination of hardware and software to enable the remote access to tools or information that typically reside on a network of IT devices.
7. Difference between Client Mail and Web Mail?
Email clients download your emails onto your computer. Using a specialized email program such as Outlook Express or Apple Mail has the advantage of giving you complete control over your email; every email you receive is placed on your computer and you can keep as many large file attachments as you want.
Checking your email through our webmail is similar to using Hotmail or Yahoo! Mail. You never actually copy your messages to your computer; in fact, you are looking at them through your web browser on somebody else"s computer. When you are not online, you are not able to see your email.
8. RAM and ROM
random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.
Pronounced rahm, acronym for read-only memory, computer memory on which data has been prerecorded. Once data has been written onto a ROM chip, it cannot be removed and can only be read. Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile.
9. Spamguard
Spam Guard is an Outlook add-in that filters email that arrives in your inbox. If the sender of any message cannot be identified then the message is moved into a spam quarantine folder. Messages deposited in the spam quarantine folder can be inspected and either deleted or approved at your leisure.
10. Firewall and Antivirus
A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
Antivirus is a software program which helps protect a computer against being infected by a virus.
11. DNS
Short for Domain Name System (or Service or Server), an Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they"re easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.example.com might translate to 198.105.232.4.
12. IPConfig
IPConfig is a command line tool used to control the network connections on Windows NT/2000/XP machines. There are three main commands: "all", "release", and "renew". IPConfig displays all current TCP/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings. Used without parameters, IPConfig displays the IP address, subnet mask, and default gateway for all adapters.
13. Trace route
Trace route is the program that shows you the route over the network between two systems, listing all the intermediate routers a connection must pass through to get to its destination. It can help you determine why your connections to a given server might be poor, and can often help you figure out where exactly the problem is. It also shows you how systems are connected to each other, letting you see how your ISP connects to the Internet as well as how the target system is connected.
Please find the technical questions:
1) What is IP Address ?
2) What are the layers of network ?
3) What are the different types of network ?
4) What is networking ?
5) What is the difference between OSI and TCP/IP Model ?
6) What is TCP/IP ?
7) What is HTTP?
8) What is Protocol ?
9) What is communication medium ?
10) What is PORT ?
11) What is SOCKET ?
12) What is the difference between PORT and SOCKET?
13) What is wireless networking ?
14) What is topology ?
15) What are the different types of topology ?
16) What is the size of IP Address?
17) What is FTP ?
18) What is SMTP ?
19) What are the different types of protocol ?
20) What is Dial-Up connection ?
21) What is Broad Band Connection?
22) What is the difference between Dial-up and broad band connection?
23) What IEEE standard for wireless networking?
Ans: 802.11g
24) What is IEEE standard ?
Ans: Institute of electrical and electronic engineer.They develop standard for networking
Posted by Chandan Patralekh at 05:41 0 comments
Thursday, 19 June 2008
Basic information on Active Directory, DNS, DHCP, RAID
DNS:A Domain Naming server is a hierarchical namespace structure designed to provide host to IP address name resolution and registration.
DNS ZONE TYPE:
Forward lookup zone: resolves names to IP address.
Reverse lookup zone:
resolves IP addresses to Host names.
AD INTEGRATED ZONE
AD–integrated DNS enables AD storage and replication of DNS zone databases. Windows 2000 & 2003 DNS servers which accommodates storing zone data in AD. When you configure a computer as a DNS server, zones are usually stored as text files on name servers — that is, all of the zones required by DNS are stored in a text file on the server computer. These text files must be synchronized among DNS name servers by using a system that requires a separate replication topology and schedule called a zone transfer However, if you use AD integrated DNS you configure a domain controller as a DNS name server, zone data is stored as an AD object and is replicated as part of domain replication.
STUB ZONE
A Stub zone is a read only copy of a zone that contains only those resources records necessary to identify the authoritative DNS servers for the actual zone. A stub zone is used to keep a parent zone aware of authoritative DNS servers for a delegated zone and thereby maintain DNS name resolution efficiently. A stub zone is conposed of (A), (NS), (SOA)
Types of DNS Records: -
A(Host):
Represents a computer or device on the network. 'A'records are the most common and most used DNS records.
PTR(Pointer):
Used for finding the DNS name that corresponds to an IP address. The PTR is found only in the reverse lookup zone.
NS(NameServer):
The NS RRs facilitate delegation by identifying DNS servers for each zone. They appear in all forward and reverse look-up zones.
SOA(Start Of Authority):
The first record in any zone file is a SOA. the SOA identifies a primary DNS name server for the zone as the best source of information for the data within that zone and as an entity processing the updates for the zone.
SRV(Service Record):
Indicates a network service offered by a host.- CNAME(Alias):an alias is hostname that refers to another hostname.
=========================================
DHCP: Is a standard for simplifing management of host IP configuration.
SUPERSCOPE: Superscope is a administrative feature of DHCP server that you can create and manage through the DHCP console. Using a Superscope you can group multiple scopes as a single administrative entity.
DHCP Authorize: This procedure is usually only needed if you are running a DHCP server on a member server. In most cases, if you are installing a DHCP server on a computer also running as a domain controller, the server is automatically authorized the first time you add the server to the DHCP console.
SCOPE: DHCP scope is a poole of IP addresses which are offered to DHCP clients.
=========================================
WHAT ARE FSMO ROLES IN ACTIVE DIRECTORY?
Windows 2000 and Windows 2003 Active directory follow the multimaster model. Under this model there are five roles which which can be held by the DCs (Domian Controllers).
The five roles are given below:
• Schema Master: The schema master domain controller controls all updates and modifications to the schema. To update the schema of a forest, you must have access to the schema master. There can be only one schema master in the whole forest.
• Domain naming master: The domain naming master domain controller controls the addition or removal of domains in the forest. There can be only one domain naming master in the whole forest.
• Infrastructure Master: The infrastructure is responsible for updating references from objects in its domain to objects in other domains. At any one time, there can be only one domain controller acting as the infrastructure master in each domain.
• Relative ID (RID) Master: The RID master is responsible for processing RID pool requests from all domain controllers in a particular domain. At any one time, there can be only one domain controller acting as the RID master in the domain.
• PDC Emulator: The PDC emulator is a domain controller that advertises itself as the primary domain controller (PDC) to workstations, member servers, and domain controllers that are running earlier versions of Windows. For example, if the domain contains computers that are not running Microsoft Windows XP Professional or Microsoft Windows 2000 client software, or if it contains Microsoft Windows NT backup domain controllers, the PDC emulator master acts as a Windows NT PDC. It is also the Domain Master Browser, and it handles password discrepancies. At any one time, there can be only one domain controller acting as the PDC emulator master in each domain in the forest.
What is replication in active directory?
REPLICATION Replication is a process of sending update information for data that has changed in the directory to other domain controllers, as a Part of the AD planning an implementation process.*2000/2003 uses MULTI-MASTER replication for the AD.
Types of UPDATES which force replication: Add, Modify, ModifyDN, delete
USN: Update sequence numbers
GUID: Globally unique identifier
REPLICATION PARTITIONS: Schema Partition: contains object and attribute definitions. In other words it contains a list of definitions that define what objects and attributes for those objects can exist in the AD.Configuration partition: contains information about the physical structure of the AD, such as the sites and domains and where DC resides in the enterprise. It is replicated to all DC's in the tree or forest.Domain partition: contains information about all AD objects that are specific to that domain, such as users, groups and other resources. All domain partition information is completely replicated to all domain controllers within the domain.
REPLICATION TOPOLOGY
KCC: Knowledge Consistency Checker: It builds the topology for the intrasite replication between the DCs. It uses only RPC to communicate with the directory service.
Bridgehead server: A point where a replication information leaves or enters a site for intersite replication.
BENIFITS
• Optimize replication for speed and bandwidth consumption between domain controllers.• Locate the closest domain controller for client logon, services, and directory searches.
• Direct a Distributed File System (DFS) client to the server that is hosting the requested data within the site.
• Replicate the system volume (SYSVOL), a collection of folders in the file system that exists on each domain controller in a domain and is required for implementation of Group Policy
=============================================================
What is RAID?
ANS: Redundant Array of Inexpensive disk is a way to increase capaxity, performance and reliablility.
RAID0: (Striping) Not really RAID as it has no fault tolerance, Data is striped across all disks, Excelent read/write performance.
RAID1: (Mirroring) Need at least 2 drives, tolerates single drive failure, often used for OS drive or boot volume.
RAID5: Requires at least 3 drives, data and parity striped across all disks, can tolerate failure of any one disk without losing data but performance does degrade.
TCP/IP MODEL:
Application Layer
Transport Layer
Internet
Network Interface
OSI MODEL
Application Layer
Presentation layer
Session layer
Transport Layer
Network Layer
Data-link Layer
Physical layer
What is a switch?
A network switch, or bridge, is a specialized device that connects multiple network segments. It's a more modern and efficient form of the ubiquitous (and outdated) network hub. A hub, also known as a repeater, is a simple device that has been used for years to connect all nodes, or computers, on a network to a central location. Each node on a network has a unique hardware address called a MAC address. A hub is known as a repeater because when a packet of data, or frame, is sent through the hub, it is repeated to each and every computer on the network.This means that if a 1 GB video is sent to one computer through the hub, the file will also be sent to all of the other computers on the hub. This is very inefficient for bandwidth management. "Hubs have two major drawbacks," says Ben deGonzague, a deployment engineer with TopCoder Software, a Glastonbury, Conn.-based software engineering firm. "First, network bandwidth is consumed as each and every frame is sent to all devices on a network. Second, your network is only as fast as the slowest device. Hubs have become obsolete with switching-based networks."A switch-based network is one that utilizes switches instead of hubs. A switch is a major upgrade to a hub. Instead of sending all network data to each and every network node, the switch will analyze the MAC address and determine where to send the data. Network bandwidth is not wasted by sending every frame to every port.So when a switch receives data for a file, if it was addressed to one computer it will only be sent there. The other computers on the network wouldn't know about it. This means that the network is now much more efficient, but it's also a step toward being more secure: "Since switches can segregate traffic from different nodes," says deGonzague, "this makes it more difficult for anyone to capture packets on your network.
What is a router?
While switches connect multiple computers, a router is required to connect multiple networks, like your LAN to the Internet. Routers work by storing large tables of networks and addresses, then using algorithms to determine the shortest routes to individual addresses within those networks. In this way efficient routers not only facilitate intra-network communications, but also play a role in overall network performance. delivering the information faster.While many consumers are familiar with small routers from companies like Linksys, which can be purchased for less than $50 at computer hardware stores, they shouldn't be confused with a proper router for business. "A typical router at home will connect your cable modem or DSL network to your internal network. This is just connecting two different networks. Routers for businesses on the other hand might have to connect several different networks," says deGonzague. Small business routers from vendors like Cisco often include management software, enabling IT staff to better manage network stability and, ultimately, performance.
Posted by Chandan Patralekh at 02:18 2 comments
Friday, 25 January 2008
How to Become a Desktop Engineer
Interview Questions
===================
A) Tell me something about yourself.
Tell about your eductaion, place you belong to, some struggle in life which shows that you have positive attitude and will to fight the odds.
B) Technical Questions:
1) What is Active Directory?
A central component of the Windows platform, Active Directory directory service provides the means to manage the identities and relationships that make up network environments. For example we can create, manage and administor users, computers and printers in the network from active directory.
2) What is DNS? Why it is used? What is "forward lookup" and "reverse lookup" in DNS? What are A records and mx records?
DNS is domain naming service and is used for resolving names to IP address and IP addresses to names. The computer understands only numbers while we can easily remember names. So to make it easier for us what we do is we assign names to computers and websites. When we use these names (Like yahoo.com) the computer uses DNS to convert to IP address (number) and it executes our request.
Forward lookup: Converting names to IP address is called forward lookup.
Reverse lookup: Resolving IP address to names is called reverse lookup.
'A' record: Its called host record and it has the mapping of a name to IP address. This is the record in DNS with the help of which DNS can find out the IP address of a name.
'MX' Record: its called mail exchanger record. Its the record needed to locate the mail servers in the network. This record is also found in DNS.
3) What id DHCP? Why it is used? What are scopes and super scopes?
DHCP: Dynamic host configuration protocol. Its used to allocate IP addresses to large number of PCs in a network environment. This makes the IP management very easy.
Scope: Scope contains IP address like subnet mask, gateway IP, DNS server IP and exclusion range which a client can use to communicate with the other PCs in the network.
Superscope: When we combine two or more scopes together its called super scope.
4) What are the types of LAN cables used? What is a cross cable?
Types of LAN cables that are in use are "Cat 5" and "Cat 6". "Cat 5" can support 100 Mbps of speed and "CAT 6" can support 1Gbps of speed.
Cross cable: Its used to connect same type of devices without using a switch/hub so that they can communicate.
5) What is the difference between a normal LAN cable and cross cable? What could be the maximum length of the LAN cable?
The way the paired wires are connected to the connector (RJ45) is different in cross cable and normal LAN cable.
The theoritical length is 100 meters but after 80 meters you may see drop in speed due to loss of signal.
6) What would you use to connect two computers without using switches? Cross cable. 7) What is IPCONFIG command? Why it is used?
IPCONFIG command is used to display the IP information assigned to a computer. Fromthe output we can find out the IP address, DNS IP address, gateway IP address assigned to that computer.
8) What is APIPA IP address? Or what IP address is assigned to the computer when the DHCP server is not available?
When DHCP server is not available the Windows client computer assignes an automatic IP address to itself so that it can communicate with the network cmputers. This ip address is called APIPA. ITs in the range of 169.254.X.X.
APIPA stands for Automatic private IP addressing. Its in the range of 169.254.X.X.
9) What is a DOMAIN? What is the difference between a domain and a workgroup? Domain is created when we install Active Directory. It's a security boundary which is used to manage computers inside the boundary. Domain can be used to centrally administor computers and we can govern them using common policies called group policies.
We can't do the same with workgroup.
10) Do you know how to configure outlook 2000 and outlook 2003 for a user?
Please visit the link below to find out how to configure outlook 2000 and outlook 2003.http://www.it.cmich.edu/quickguides/qg_outlook2003_server.asp
11) What is a PST file and what is the difference between a PST file and OST file? What file is used by outlook express?
PST file is used to store the mails locally when using outlook 2000 or 2003. OST file is used when we use outlook in cached exchanged mode. Outlook express useds odb file.
12) What is BSOD? What do you do when you get blue screen in a computer? How do you troubleshoot it?
BSOD stands for blue screen of Death. when there is a hardware or OS fault due to which the windows OS can run it give a blue screen with a code. Best way to resolve it is to boot the computer is "LAst known good configuration". If this doesn't work than boot the computer in safe mode. If it boots up than the problemis with one of the devices or drivers.
13) What is RIS? What is Imaging/ghosting?
RIS stands for remote installation services. You save the installed image on a windows server and then we use RIS to install the configured on in the new hardware. We can use it to deploy both server and client OS. Imaging or ghosting also does the same job of capturing an installed image and then install it on a new hardware when there is a need. We go for RIS or iamging/ghosting because installing OS everytime using a CD can be a very time consuming task. So to save that time we can go for RIS/Ghosting/imaging.
14) What is VPN and how to configure it?
VPN stands for Virtual private network. VPN is used to connect to the corporate network to access the resources like mail and files in the LAN. VPN can be configured using the stepsmentioned in the KB: http://support.microsoft.com/kb/305550
15) Your computer slowly drops out of network. A reboot of the computer fixes the problem. What to do to resolve this issue?
Update the network card driver.
16) Your system is infected with Virus? How to recover the data?
Install another system. Insall the OS with the lates pathces, Antivirus with latest updates. Connect the infected HDD as secondary drive in the system. Once done scan and clean the secondary HDD. Once done copy the files to the new system.
17) How to join a system to the domain? What type of user can add a system to the domain?
Please visit the article below and read "Adding the Workstation to the Domain"
http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/directory/activedirectory/stepbystep/domxppro.mspx
18) What is the difference between a switch and a hub?
Switch sends the traffic to the port to which its meant for. Hub sends the traffic to all the ports.
19) What is a router? Why we use it?
Router is a switch which uses routing protocols to process and send the traffic. It also receives the traffic and sends it across but it uses the routing protocols to do so.
20) What are manageable and non manageable switches?
Switches which can be administered are calledmanageable switches. For example we can create VLAN for on such switch. On no manageable swiches we can't do so.
Basic information on Active Directory, DNS, DHCP, RAID
DNS:A Domain Naming server is a hierarchical namespace structure designed to provide host to IP address name resolution and registration.
DNS ZONE TYPE:
Forward lookup zone: resolves names to IP address.
Reverse lookup zone:
resolves IP addresses to Host names.
AD INTEGRATED ZONE
AD–integrated DNS enables AD storage and replication of DNS zone databases. Windows 2000 & 2003 DNS servers which accommodates storing zone data in AD. When you configure a computer as a DNS server, zones are usually stored as text files on name servers — that is, all of the zones required by DNS are stored in a text file on the server computer. These text files must be synchronized among DNS name servers by using a system that requires a separate replication topology and schedule called a zone transfer However, if you use AD integrated DNS you configure a domain controller as a DNS name server, zone data is stored as an AD object and is replicated as part of domain replication.
STUB ZONE
A Stub zone is a read only copy of a zone that contains only those resources records necessary to identify the authoritative DNS servers for the actual zone. A stub zone is used to keep a parent zone aware of authoritative DNS servers for a delegated zone and thereby maintain DNS name resolution efficiently. A stub zone is conposed of (A), (NS), (SOA)
Types of DNS Records: -
A(Host):
Represents a computer or device on the network. 'A'records are the most common and most used DNS records.
PTR(Pointer):
Used for finding the DNS name that corresponds to an IP address. The PTR is found only in the reverse lookup zone.
NS(NameServer):
The NS RRs facilitate delegation by identifying DNS servers for each zone. They appear in all forward and reverse look-up zones.
SOA(Start Of Authority):
The first record in any zone file is a SOA. the SOA identifies a primary DNS name server for the zone as the best source of information for the data within that zone and as an entity processing the updates for the zone.
SRV(Service Record):
Indicates a network service offered by a host.- CNAME(Alias):an alias is hostname that refers to another hostname.
=========================================
DHCP: Is a standard for simplifing management of host IP configuration.
SUPERSCOPE: Superscope is a administrative feature of DHCP server that you can create and manage through the DHCP console. Using a Superscope you can group multiple scopes as a single administrative entity.
DHCP Authorize: This procedure is usually only needed if you are running a DHCP server on a member server. In most cases, if you are installing a DHCP server on a computer also running as a domain controller, the server is automatically authorized the first time you add the server to the DHCP console.
SCOPE: DHCP scope is a poole of IP addresses which are offered to DHCP clients.
=========================================
WHAT ARE FSMO ROLES IN ACTIVE DIRECTORY?
Windows 2000 and Windows 2003 Active directory follow the multimaster model. Under this model there are five roles which which can be held by the DCs (Domian Controllers).
The five roles are given below:
• Schema Master: The schema master domain controller controls all updates and modifications to the schema. To update the schema of a forest, you must have access to the schema master. There can be only one schema master in the whole forest.
• Domain naming master: The domain naming master domain controller controls the addition or removal of domains in the forest. There can be only one domain naming master in the whole forest.
• Infrastructure Master: The infrastructure is responsible for updating references from objects in its domain to objects in other domains. At any one time, there can be only one domain controller acting as the infrastructure master in each domain.
• Relative ID (RID) Master: The RID master is responsible for processing RID pool requests from all domain controllers in a particular domain. At any one time, there can be only one domain controller acting as the RID master in the domain.
• PDC Emulator: The PDC emulator is a domain controller that advertises itself as the primary domain controller (PDC) to workstations, member servers, and domain controllers that are running earlier versions of Windows. For example, if the domain contains computers that are not running Microsoft Windows XP Professional or Microsoft Windows 2000 client software, or if it contains Microsoft Windows NT backup domain controllers, the PDC emulator master acts as a Windows NT PDC. It is also the Domain Master Browser, and it handles password discrepancies. At any one time, there can be only one domain controller acting as the PDC emulator master in each domain in the forest.
What is replication in active directory?
REPLICATION Replication is a process of sending update information for data that has changed in the directory to other domain controllers, as a Part of the AD planning an implementation process.*2000/2003 uses MULTI-MASTER replication for the AD.
Types of UPDATES which force replication: Add, Modify, ModifyDN, delete
USN: Update sequence numbers
GUID: Globally unique identifier
REPLICATION PARTITIONS: Schema Partition: contains object and attribute definitions. In other words it contains a list of definitions that define what objects and attributes for those objects can exist in the AD.Configuration partition: contains information about the physical structure of the AD, such as the sites and domains and where DC resides in the enterprise. It is replicated to all DC's in the tree or forest.Domain partition: contains information about all AD objects that are specific to that domain, such as users, groups and other resources. All domain partition information is completely replicated to all domain controllers within the domain.
REPLICATION TOPOLOGY
KCC: Knowledge Consistency Checker: It builds the topology for the intrasite replication between the DCs. It uses only RPC to communicate with the directory service.
Bridgehead server: A point where a replication information leaves or enters a site for intersite replication.
BENIFITS
• Optimize replication for speed and bandwidth consumption between domain controllers.• Locate the closest domain controller for client logon, services, and directory searches.
• Direct a Distributed File System (DFS) client to the server that is hosting the requested data within the site.
• Replicate the system volume (SYSVOL), a collection of folders in the file system that exists on each domain controller in a domain and is required for implementation of Group Policy
=============================================================
What is RAID?
ANS: Redundant Array of Inexpensive disk is a way to increase capaxity, performance and reliablility.
RAID0: (Striping) Not really RAID as it has no fault tolerance, Data is striped across all disks, Excelent read/write performance.
RAID1: (Mirroring) Need at least 2 drives, tolerates single drive failure, often used for OS drive or boot volume.
RAID5: Requires at least 3 drives, data and parity striped across all disks, can tolerate failure of any one disk without losing data but performance does degrade.
TCP/IP MODEL:
Application Layer
Transport Layer
Internet
Network Interface
OSI MODEL
Application Layer
Presentation layer
Session layer
Transport Layer
Network Layer
Data-link Layer
Physical layer
What is a switch?
A network switch, or bridge, is a specialized device that connects multiple network segments. It's a more modern and efficient form of the ubiquitous (and outdated) network hub. A hub, also known as a repeater, is a simple device that has been used for years to connect all nodes, or computers, on a network to a central location. Each node on a network has a unique hardware address called a MAC address. A hub is known as a repeater because when a packet of data, or frame, is sent through the hub, it is repeated to each and every computer on the network.This means that if a 1 GB video is sent to one computer through the hub, the file will also be sent to all of the other computers on the hub. This is very inefficient for bandwidth management. "Hubs have two major drawbacks," says Ben deGonzague, a deployment engineer with TopCoder Software, a Glastonbury, Conn.-based software engineering firm. "First, network bandwidth is consumed as each and every frame is sent to all devices on a network. Second, your network is only as fast as the slowest device. Hubs have become obsolete with switching-based networks."A switch-based network is one that utilizes switches instead of hubs. A switch is a major upgrade to a hub. Instead of sending all network data to each and every network node, the switch will analyze the MAC address and determine where to send the data. Network bandwidth is not wasted by sending every frame to every port.So when a switch receives data for a file, if it was addressed to one computer it will only be sent there. The other computers on the network wouldn't know about it. This means that the network is now much more efficient, but it's also a step toward being more secure: "Since switches can segregate traffic from different nodes," says deGonzague, "this makes it more difficult for anyone to capture packets on your network.
What is a router?
While switches connect multiple computers, a router is required to connect multiple networks, like your LAN to the Internet. Routers work by storing large tables of networks and addresses, then using algorithms to determine the shortest routes to individual addresses within those networks. In this way efficient routers not only facilitate intra-network communications, but also play a role in overall network performance. delivering the information faster.While many consumers are familiar with small routers from companies like Linksys, which can be purchased for less than $50 at computer hardware stores, they shouldn't be confused with a proper router for business. "A typical router at home will connect your cable modem or DSL network to your internal network. This is just connecting two different networks. Routers for businesses on the other hand might have to connect several different networks," says deGonzague. Small business routers from vendors like Cisco often include management software, enabling IT staff to better manage network stability and, ultimately, performance.
Windows Server Questions
1.What are the Features of windows2003?
ACTIVE DIRECTORY
Easier Deployment and Management
ADMT version 2.0—migrates password from NT4 to 2000 to 20003 or from 2000 to 2003
Domain Rename--- supports changing Domain Name System and/or NetBios name
Schema Redefine--- Allows deactivation of attributes and class definitions in the Active directory schema
AD/AM--- Active directory in application mode is a new capability of AD that addresses certain deployment scenarios related to directory enabled applications
Group Policy Improvements----introduced GPMC tool to manage group policy
UI—Enhanced User Interface
Grater Security
Cross-forest Authentication
Cross-forest Authorization
Cross-certification Enhancements
IAS and Cross-forest authentication
Credential Manager
Software Restriction Policies
Improved Performance and Dependability
Easier logon for remote offices
Group Membership replication enhancements
Application Directory Partitions
Install Replica from media
Dependability Improvements--- updated Inter-Site Topology Generator (ISTG) that scales better by supporting forests with a greater number of sites than Windows 2000.
FILE AND PRINT SERVICES
Volume shadow copy service
NTFS journaling file system
EFS
Improved CHDSK Performance
Enhanced DFS and FRS
Shadow copy of shared folders
Enhanced folder redirection
Remote document sharing (WEBDAV)
IIS
Fault-tolerant process architecture----- The IIS 6.0 fault-tolerant process architecture isolates Web sites and applications into self-contained units called application pools
Health Monitoring---- IIS 6.0 periodically checks the status of an application pool with automatic restart on failure of the Web sites and applications within that application pool, increasing application availability. IIS 6.0 protects the server, and other applications, by automatically disabling Web sites and applications that fail too often within a short amount of time
Automatic Process Recycling--- IIS 6.0 automatically stops and restarts faulty Web sites and applications based on a flexible set of criteria, including CPU utilization and memory consumption, while queuing requests
Rapid-fail Protection---- If an application fails too often within a short amount of time, IIS 6.0 will automatically disable it and return a "503 Service Unavailable" error message to any new or queued requests to the application
Edit-While-Running
2.What are the Difference between NT & 2000?
NT SAM database is a flat database. Where as in windows 2000 active directory database is a hierarchical database.
In windows NT only PDC is having writable copy of SAM database but the BDC is only read only database. In case of Windows 2000 both DC and ADC is having write copy of the database
Windows NT will not support FAT32 file system. Windows 2000 supports FAT32
Default authentication protocol in NT is NTLM (NT LAN manager). In windows 2000 default authentication protocol is Kerberos V5.
Windows 2000 depends and Integrated with DNS. NT user Netbios names
Active Directory can be backed up easily with System state data
3.What Difference between 2000 & 2003?
Application Server mode is introduced in windows 2003
Possible to configure stub zones in windows 2003 DNS
Volume shadow copy services is introduced
Windows 2003 gives an option to replicate DNS data b/w all DNS servers in forest or All DNS servers in the domain.
Refer Question 1 for all Enhancements
4.What Difference between PDC & BDC?
PDC contains a write copy of SAM database where as BDC contains read only copy of SAM database. It is not possible to reset a password or create objects with out PDC in Windows NT.
5.What are Difference between DC & ADC?
There is no difference between in DC and ADC both contains write copy of AD. Both can also handles FSMO roles (If transfers from DC to ADC). It is just for identification. Functionality wise there is no difference.
6.What is DNS & WINS
DNS is a Domain Naming System, which resolves Host names to IP addresses. It uses fully qualified domain names. DNS is a Internet standard used to resolve host names
WINS is a Windows Internet Name Service, which resolves Netbios names to IP Address. This is proprietary for Windows
7.How may Types of DNS Servers
Primary DNS
Secondary DNS
Active Directory Integrated DNS
Forwarder
Caching only DNS
8.If DHCP is not available what happens to the client ?
Client will not get IP and it cannot be participated in network . If client already got the IP and having lease duration it use the IP till the lease duration expires.
9.what are the different types of trust relationships ?
Implicit Trusts
Explicit Trusts—NT to Win2k or Forest to Forest
10.what is the process of DHCP for getting the IP address to the client ?
There is a four way negotiation process b/w client and server
DHCP Discover (Initiated by client)
DHCP Offer (Initiated by server)
DHCP Select (Initiated by client)
DHCP Acknowledgment (Initiated by Server)
DHCP Negative Acknowledgment (Initiated by server if any issues after DHCP offer)
11.Difference between FAT,NTFS & NTFSVersion5 ?
NTFS Version 5 features
Encryption is possible
We can enable Disk Quotas
File compression is possible
Sparse files
Indexing Service
NTFS change journal
In FAT file system we can apply only share level security. File level protection is not possible. In NTFS we can apply both share level as well as file level security
NTFS supports large partition sizes than FAT file systems
NTFS supports long file names than FAT file systems
12.What are the port numbers for FTP, Telnet, HTTP, DNS ?
FTP-21, Telnet – 23, HTTP-80, DNS-53, Kerberos-88, LDAP-389
13.what are the different types of profiles in 2000 ?
Local Profiles
Roaming profiles
Mandatory Profiles
14.what is the database files used for Active Directory ? ?
The key AD database files—edb.log, ntds.dit, res1.log, res2.log, and edb.chk—all of which reside in \%systemroot%\ntds on a domain controller (DC) by default. During AD installation, Dcpromo lets you specify alternative locations for these log files and database files
NTDS.DIT
15.What is the location of AD Database ?
%System root%/NTDS/NTDS>DIT
16.What is the authentication protocol used in NT ?
NTLM (NT LAN Manager)
17.What is subnetting and supernetting ?
Subnetting is the process of borrowing bits from the host portion of an address to provide bits for identifying additional sub-networks
Supernetting merges several smaller blocks of IP addresses (networks) that are continuous into one larger block of addresses. Borrowing network bits to combine several smaller networks into one larger network does supernetting
18.what is the use of terminal services ?
Terminal services can be used as Remote Administration mode to administer remotely as well as Application Server Mode to run the application in one server and users can login to that server to user that application.
19.what is the protocol used for terminal services ?
RDP
20.what is the port number for RDP ?
3389
Windows Server 2003 Interview Questions
1. How do you double-boot a Win 2003 server box?
The Boot.ini file is set as read-only, system, and hidden to prevent unwanted editing. To change the Boot.ini timeout and default settings, use the System option in Control Panel from the Advanced tab and select Startup
2.What do you do if earlier application doesn’t run on Windows Server 2003?
When an application that ran on an earlier legacy version of Windows cannot be loaded during the setup function or if it later malfunctions, you must run the compatibility mode function. This is accomplished by right-clicking the application or setup program and selecting Properties –> Compatibility –> selecting the previously supported operating system.
3.If you uninstall Windows Server 2003, which operating systems can you revert to?
Win ME, Win 98, 2000, XP. Note, however, that you cannot upgrade from ME and 98 to Windows Server 2003
4.How do you get to Internet Firewall settings?
Start –> Control Panel –> Network and Internet Connections –> Network Connections
5.What is Active Directory?
Active Directory is a network-based object store and service that locates and manages resources, and makes these resources available to authorized users and groups. An underlying principle of the Active Directory is that everything is considered an object—people, servers, workstations, printers, documents, and devices. Each object has certain attributes and its own security access control list (ACL).
6.Where are the Windows NT Primary Domain Controller (PDC) and its Backup Domain Controller (BDC) in Server 2003?
The Active Directory replaces them. Now all domain controllers share a multimaster peer-to-peer read and write relationship that hosts copies of the Active Directory.
7.How long does it take for security changes to be replicated among the domain controllers?
Security-related modifications are replicated within a site immediately. These changes include account and individual user lockout policies, changes to password policies, changes to computer account passwords, and modifications to the Local Security Authority (LSA).
8.What’s new in Windows Server 2003 regarding the DNS management?
When DC promotion occurs with an existing forest, the Active Directory Installation Wizard contacts an existing DC to update the directory and replicate from the DC the required portions of the directory. If the wizard fails to locate a DC, it performs debugging and reports what caused the failure and how to fix the problem. In order to be located on a network, every DC must register in DNS DC locator DNS records. The Active Directory Installation Wizard verifies a proper configuration of the DNS infrastructure. All DNS configuration debugging and reporting activity is done with the Active Directory Installation Wizard.
9.When should you create a forest?
Organizations that operate on radically different bases may require separate trees with distinct namespaces. Unique trade or brand names often give rise to separate DNS identities. Organizations merge or are acquired and naming continuity is desired. Organizations form partnerships and joint ventures. While access to common resources is desired, a separately defined tree can enforce more direct administrative and security restrictions.
10.How can you authenticate between forests?
Four types of authentication are used across forests:
(1) Kerberos and NTLM network logon for remote access to a server in another forest
(2) Kerberos and NTLM interactive logon for physical logon outside the user’s home forest
(3) Kerberos delegation to N-tier application in another forest
(4) user principal name (UPN) credentials.
11.What snap-in administrative tools are available for Active Directory?
Active Directory Domains and Trusts Manager, Active Directory Sites and Services Manager, Active Directory Users and Group Manager, Active Directory Replication (optional, available from the Resource Kit), Active Directory Schema Manager (optional, available from adminpack)
12.What types of classes exist in Windows Server 2003 Active Directory?
Structural class. The structural class is important to the system administrator in that it is the only type from which new Active Directory objects are created. Structural classes are developed from either the modification of an existing structural type or the use of one or more abstract classes.
Abstract class. Abstract classes are so named because they take the form of templates that actually create other templates (abstracts) and structural and auxiliary classes. Think of abstract classes as frameworks for the defining objects.
Auxiliary class. The auxiliary class is a list of attributes. Rather than apply numerous attributes when creating a structural class, it provides a streamlined alternative by applying a combination of attributes with a single include action.
88 class. The 88 class includes object classes defined prior to 1993, when the 1988 X.500 specification was adopted. This type does not use the structural, abstract, and auxiliary definitions, nor is it in common use for the development of objects in Windows Server 2003 environments.
13.How do you delete a lingering object?
Windows Server 2003 provides a command called Repadmin that provides the ability to delete lingering objects in the Active Directory.
14.What is Global Catalog?
The Global Catalog authenticates network user logons and fields inquiries about objects across a forest or tree. Every domain has at least one GC that is hosted on a domain controller. In Windows 2000, there was typically one GC on every site in order to prevent user logon failures across the network.
15.How is user account security established in Windows Server 2003?
When an account is created, it is given a unique access number known as a security identifier (SID). Every group to which the user belongs has an associated SID. The user and related group SIDs together form the user account’s security token, which determines access levels to objects throughout the system and network. SIDs from the security token are mapped to the access control list (ACL) of any object the user attempts to access.
16.If I delete a user and then create a new account with the same username and password, would the SID and permissions stay the same?
No. If you delete a user account and attempt to recreate it with the same user name and password, the SID will be different.
17.What do you do with secure sign-ons in an organization with many roaming users?
Credential Management feature of Windows Server 2003 provides a consistent single sign-on experience for users. This can be useful for roaming users who move between computer systems. The Credential Management feature provides a secure store of user credentials that includes passwords and X.509 certificates.
18.Anything special you should do when adding a user that has a Mac?
"Save password as encrypted clear text" must be selected on User Properties Account Tab Options, since the Macs only store their passwords that way.
19.What remote access options does Windows Server 2003 support?
Dial-in, VPN, dial-in with callback.
20.Where are the documents and settings for the roaming profile stored?
All the documents and environmental settings for the roaming user are stored locally on the system, and, when the user logs off, all changes to the locally stored profile are copied to the shared server folder. Therefore, the first time a roaming user logs on to a new system the logon process may take some time, depending on how large his profile folder is.
21.Where are the settings for all the users stored on a given machine?
C:\Document and Settings\All Users
22.What languages can you use for log-on scripts?
JavaScript, VBScript, DOS batch files (.com, .bat, or even .exe)
Network Questions - I
1. What is the difference between TCP and UDP
TCP is a connection oriented protocol, which means that everytime a packet is sent say from host A to B, we will get an acknowledgement. Whereas UDP on the other hand, is a connection less protocol.
Where will it be used : TCP -> Say you have a file transfer and you need to ensure that the file reaches intact, and time is not a factor, in such a case we can use TCP.
UDP-> Media Streaming, question is say you are watching a movie…would you prefer that your movie comes..perfectly….but u need to wait a long time before you see the next frame ?..or would you prefer the movie to keep streaming…Yes…The second option is definely better….This is when we need UDP
2. What is a MAC address?
MAC is a machines Physical address, The internet is addressed based on a logical addressing approach. Say, when the packet reaches say the bridge connection a LAN, the question is..how does it identify, which computer it needs to send the packet to. For this it uses the concept of ARP, Address Resolution Protocol, which it uses over time to build up a table mapping from the Logical addresses to the Physical addresses. Each computer is identified using its MAC/Physical address ( u can use the ipconfig -all option to get ur MAC address).
3. What is MTU?
The MTU is the “Maximum Transmission Unit” used by the TCP protocol. TCP stands for Transmission Control Prototcol. The MTU determines the size of packets used by TCP for each transmission of data. Too large of an MTU size may mean retransmissions if the packet encounters a router along its route that can’t handle that large a packet. Too small of an MTU size means relatively more overhead and more acknowledgements that have to be sent and handled. The MTU is rated in “octets” or groups of 8 bits. The so-called “official” internet standard MTU is 576, but the standard rating for ethernet is an MTU of 1500.
4. Difference Between. Switch , Hub, Router..
Hub: 1.it is a layer1 device..used to connect various machine on Lan.
2.It forwards broadcast by default.
3.It supports one collision domain and one broadcast domain.
4.it works on Bus topology resulting less speed.
Switch: 1. A layer2 device.
2. Forward broadcast first time only.
3. one broadcast domain & collision domains depends on no. of ports.
4.It is based on Star Topology giving 100mbps to every pc on Lan.
Router: 1. Does not Broadcast by default.
2. breaks up Broadcast domain.
3. Also called Layer3 switch.
5. VPN.....
VPN(Virtual Private Network )… these are basically the logical networks on the physical line… you can have many VPN over same line..
Need of VPN arises when your company need to increase the network but don’t want to buy any more switches.. take an eg. your dept. your room is packed with employees and ur company need to add 4 more persons to ur deptt. what will they do.. the solution is to create VPN’s…you can configure the switch ports in other deptts. and create a specific VLAN of ur deptt. So that the persons can sit there and access to the required pcs.
6. ARP & RARP.....
Stands for Address Resolution Protocol…whenever a request is sent by a node on one network to the node on another network the Physical address(MAC) is required and for this the IP address need to be flow over the network..whenever a router with that network (IP) gets the msg. the required MAC address is sent through the network this process of converting the IP address to MAC address is Called ARP..and the reverse thats the convertion of the Mac address to the IP address is called RARP ( Reverse Address Resolution Protocol)
7. What is the difference between layer 2 and layer 3 in the OSI model?
Layer 2 is responsible for switching data whereas Layer 3 is responsible for routing the data.
Layer3: With information gathered from user, Internet protocol make one IP packet with source IP and Destination IP and other relevant information. It can then route packet through router to the destination.
Layer2: Soon after it receives IP packet from layer 3, it encapsulate it with frame header (ATM header in case of ATM technology) and send it out for switching. In case of Ethernet it will send data to MAC address there by it can reach to exact destination.
• Important Port Numbers:
HTTP ---------- 80
FTP ------------ 20,21
TelNet ---------- 23
SMTP ---------- 25
DNS ----------- 53
TFTP ----------- 69
SNMP ---------- 161
RIP ------------- 520
IMAP 4--------- 143
IMAP 3 --------- 220
RPC ------------ 135
LDAP ---------- 389
Net Stat -------- 15
WINS ---------- 42
BootP ---------- 67
DHCP ---------- 68
POP2 ---------- 109
POP3 ---------- 110
Net BIOS ------ 139
SSL(HTTPS) --- 443
SQL Server ---- 1433
NFS ------------ 2049
SSH ------------ 22
RAP ----------- 38
BGP ----------- 179
Monday, September 15, 2008 Selva No comments
• Layers & Protocols
Layers & Protocols
1. OSI Model ( Open System Interface ) - 7 Layers
2. TCP / IP Model - 4 Layers
OSI MODEL :
1. Application Layer --------- Data
2. Presentation Layer ------- Data
3. Session Layer -------------Data
4. Transport Layer ----------Segments
5. Network Layer ----------- Packets ( Router – IP )
6. Data Link Layer ---------- Frames ( Switch & Bridge – MAC )
7. Physical Layer ------------ Dealing with Bits ( Repeater & Hub )
TCP / IP MODEL :
1. Application Layer
2. Transport Layer
3. Internet Layer
4. Network Access Layer
OSI LAYER : TCP / IP LAYER
Application Layer | Application Layer
Presentation Layer | Application Layer
Session Layer | Application Layer
Transport Layer - Transport Layer
Network Layer - Internet Layer
Data Link |Network Access Layer
Physical Layer | Network Access Layer
PROTOCOLS :
Physical & Data link Layer – Ethernet, Token Ring and FDDI
Network & Internet Layer - IP,ICMP,ARP,RARP,PPP,HDLC,SLIP
Transport Layer - TCP and UDP
Application Layer - FTP,TFTP,DNS,PROXY,SNMP,SMTP,TELNET,POP3
HTTP,REMOTE LOGIN
TCP ------------ Transmission Control Protocol
UDP------------ User Datagram Protocol
PPP-------------Point-to-Point Protocol
HDLC-----------High Level Data Link Protocol
SLIP------------Serial Line Internet Protocol
RIP-------------Routing Information Protocol
IGRP-----------Interior Gateway Routing Protocol
EIGRP----------Enhanced IGRP
BGP------------Border Gateway protocol
OSPF-----------Open Shortest Path First
IS-IS-----------Intermediate System - Intermediate System
IP--------------Internet Protocol
ICMP----------Internet Control Messaging Protocol
ARP-----------Address Resolution Protocol
RARP----------Reverse Address Resolution Protocol
FTP------------File Transfer Protocol
TFTP----------Trivial File Transfer Protocol
SNMP---------Simple Network Management Protocol
SMTP---------Simple Mail Transfer Protocol
Differance between DNS & WINS
DNS refers to the Domain Name System -- a widely used service in networks all over the world. DNS was created to serve the Internet Network, but also our LAN (Local Area Network).
WINS, on the other hand, refers to Windows Internet Naming Service created by Microsoft and was used in the older Windows NT4 networks as the services provided by the domain, were heavily depended on it.
Today, WINS servers are not that common except in specific applications and network conditions where they must exist. Because the majority of networks use DNS these days, Windows 2000 and 2003 have migrated away from WINS and use DNS mainly. While both services do identical jobs, that is, translate domains and hostnames into IP addresses, DNS has become the number one standard for name resolution and it surely won't change for a long time!
what is WORKGROUP?
In computer networking, a workgroup is a collection of computers on a local area network (LAN) that share common resources and responsibilities. Workgroups provide easy sharing of files, printers and other network resources. Being a peer-to-peer (P2P) network design, each workgroup computer may both share and access resources if configured to do so.
The Microsoft Windows family of operating systems supports assigning of computers to named workgroups. Macintosh networks offer a similiar capability through the use of AppleTalk zones. The Open Source software package Samba allows Unix and Linux systems to join existing Windows workgroups.
Workgroups are designed for small LANs in homes, schools, and small businesses. A Windows Workgroup, for example, functions best with 15 or fewer computers. As the number of computers in a workgroup grows, workgroup LANs eventually become too difficult to administer and should be replaced with alternative solutions like domains or other client/server approaches.
DHCP Server Interview Questions and Answers
DHCP Server Interview Questions and Answers
1. What is DHCP?
DHCP stands for "Dynamic Host Configuration Protocol".
2.What is DHCP's purpose?
DHCP's purpose is to enable individual computers on an IP network to extract
their configurations from a server (the 'DHCP server') or servers, in particular,
servers that have no exact information about the individual computers until they
request the information. The overall purpose of this is to reduce the work
necessary to administer a large IP network. The most significant piece of
information distributed in this manner is the IP address.
3. Can DHCP work with AppleTalk or IPX?
No, it is too tied to IP. Furthermore, they don't need it since they have always
had automated mechanisms for assigning their own network addresses.
4. Who Created It? How Was It Created?
DHCP was created by the Dynamic Host Configuration Working Group of the
Internet Engineering Task Force (IETF; a volunteer organization which defines
protocols for use on the Internet). As such, it's definition is recorded in an
Internet RFC and the Internet Activities Board (IAB) is asserting its status as to
Internet Standardization. As of this writing (June 1998), DHCP is an Internet
Draft Standard Protocol and is Elective. BOOTP is an Internet Draft Standard
Protocol and is recommended. For more information on Internet standardization,
see RFC2300 (May 1998)
5. How is it different than BOOTP or RARP?
DHCP is based on BOOTP and maintains some backward compatibility. The main
difference is that BOOTP was designed for manual pre-configuration of the host
information in a server database, while DHCP allows for dynamic allocation of
network addresses and configurations to newly attached hosts. Additionally,
DHCP allows for recovery and reallocation of network addresses through a
leasing mechanism.
RARP is a protocol used by Sun and other vendors that allows a computer to find
out its own IP number, which is one of the protocol parameters typically passed
to the client system by DHCP or BOOTP. RARP doesn't support other parameters
and using it, a server can only serve a single LAN. DHCP and BOOTP are
designed so they can be routed.
6.How is it different than VLANs?
DHCP and VLANs, which are very different in concept, are sometimes cited as
different solutions to the same problem. While they have a goal in common
(easing moves of networked computers), VLANs represent a more revolutionary
change to a LAN than DHCP. A DHCP server and forwarding agents can allow you
to set things up so that you can unplug a client computer from one network or
subnet and plug it into another and have it come alive immediately, it having
been reconfigured automatically. In conjunction to Dynamic DNS, it could
automatically be given its same name in its new place. VLAN-capable LAN
equipment with dynamic VLAN assignment allows you to configure things so a
client computer can be plugged into any port and have the same IP number (as
well as name) and be on the same subnet. The VLAN-capable network either has
its own configuration that lists which MAC addresses are to belong to each VLAN,
or it makes the determination from the source IP address of the IP packets that
the client computer sends. Some differences in the two approaches:
DHCP handles changes by reconfiguring the client while a VLAN-capable
network handles it by reconfiguring the network port the client is moved to.
DHCP dynamic reconfiguration requires a DHCP server, forwarding agent
in each router, and DHCP capability in each client's TCP/IP support. The
analogous capability in VLANs requires that all hubs throughout the
network be VLAN-capable, supporting the same VLAN scheme. To this
point VLAN support is proprietary with no vendor interoperability, but
standards are being developed.
DHCP can configure a new client computer for you while a VLAN-capable
network can't.
DHCP is generally aimed at giving "easy moves" capability to networks
that are divided into subnets on a geographical basis, or on separate
networks. VLANs are generally aimed at allowing you to set up subnets
on some basis other than geographical, e.g. instead of putting everyone
in one office on the same subnet, putting each person on a subnet that
has access to the servers that that person requires.
There is an issue with trying to use DHCP (or BOOTP) and VLANs at the same
time, in particular, with the scheme by which the VLAN-capable network
determines the client's VLAN based upon the client computer's source IP
address. Doing so assumes the client computer is already configured, which
precludes the use of network to get the configuration information from a DHCP
or BOOTP server.
7. What protocol and port does DHCP use?
DHCP, like BOOTP runs over UDP, utilizing ports 67 and 68.
8. What is an IP address?
An IP address (also called an IP number) is a number (typically written as four
numbers separated by periods, i.e. 107.4.1.3 or 84.2.1.111) which uniquely
identifies a computer that is making use of the Internet. It is analogous to your
telephone number in that the telephone number is used by the telephone
network to direct calls to you. The IP address is used by the Internet to direct
data to your computer, e.g. the data your web browser retrieves and displays
when you surf the net. One task of DHCP is to assist in the problem of getting a
functional and unique IP number into the hands of the computers that make use
of the Internet.
9. What is a MAC address?
A MAC address (also called an Ethernet address or an IEEE MAC address) is a
number (typically written as twelve hexadecimal digits, 0 through 9 and A
through F, or as six hexadecimal numbers separated by periods or colons, i.e.
0080002012ef, 0:80:0:2:20:ef) which uniquely identifes a computer that has an
Ethernet interface. Unlike the IP number, it includes no indication of where your
computer is located. In DHCP's typical use, the server uses a requesting
computer's MAC address to uniquely identify it.
10. What is a DHCP lease?
A DHCP lease is the amount of time that the DHCP server grants to the DHCP
client permission to use a particular IP address. A typical server allows its
administrator to set the lease time.
11. What is a Client ID?
What is termed the Client ID for the purposes of the DHCP protocol is whatever
is used by the protocol to identify the client computer. By default, DHCP
implementations typically employ the client's MAC address for this purpose, but
the DHCP protocol allows other options. Some DHCP implementations have a
setup option to specify the client ID you want. One alternative to the MAC
address is simply a character string of your choice. In any case, in order for
DHCP to function, you must be certain that no other client is using the client ID
you choose, and you must be sure the DHCP server will accept it.
12.Can DHCP support statically defined addresses?
Yes. At least there is nothing in the protocol to preclude this and one expects it
to be a feature of any DHCP server. This is really a server matter and the client
should work either way. The RFC refers to this as manual allocation.
13. How does DHCP and BOOTP handle multiple subnets?
For the situations where there is more than one LAN, each with its own subnet
number, there are two ways. First of all, you can set up a seperate server on
each subnet. Secondly, a feature of some routers known as "BOOTP forwarding"
to forward DHCP or BOOTP requests to a server on another subnet and to
forward the replies back to the client. The part of such a router (or server acting
as a router) that does this is called a "BOOTP forwarding agent". Typically you
have to enable it on the interface to the subnet to be served and have to
configure it with the IP address of the DHCP or BOOTP server. On a Cisco router,
the address is known as the "UDP Helper Address".
14. Can a BOOTP client boot from a DHCP server?
Only if the DHCP server is specifically written to also handle BOOTP queries.
15. Can a DHCP client boot from a BOOTP server?
Only if the DHCP client were specifically written to make use of the answer from
a BOOTP server. It would presumably treat a BOOTP reply as an unending lease
on the IP address.
In particular, the TCP/IP stack included with Windows 95 does not have this
capability.
16. Is a DHCP server "supposed to" be able to support a BOOTP client?
The RFC on such interoperability (1534) is clear: "In summary, a DHCP server:
... MAY support BOOTP clients," (section 2). The word "MAY" indicates such
support, however useful, is left as an option.
A source of confusion on this point is the following statement in section 1.5 of
RFC 1541: "DHCP must provide service to existing BOOTP clients." However, this
statement is one in a list of "general design goals for DHCP", i.e. what the
designers of the DHCP protocol set as their own goals. It is not in a list of
requirements for DHCP servers.
17. Is a DHCP client "supposed to" be able to use a BOOTP server?
The RFC on such interoperability (1534) is clear: "A DHCP client MAY use a reply
from a BOOTP server if the configuration returned from the BOOTP server is
acceptable to the DHCP client." (section 3). The word "MAY" indicates such
support, however useful, is left as an option.
18. Can a DHCP client or server make a DNS server update the client's DNS entry to match the client's dynamically assigned address?
RFCs 2136 and 2137 indicate a way in which DNS entries can be updated
dynamically. Using this requires a DNS server that supports this feature and a
DHCP server that makes use of it. The RFCs are very recent (as of 5/97) and
implementations are few. In the mean time, there are DNS and DHCP servers
that accomplish this through proprietary means.
19. Can a DHCP server back up another DHCP server?
You can have two or more servers handing out leases for different addresses. If
each has a dynamic pool accessible to the same clients, then even if one server
is down, one of those clients can lease an address from the other server.
However, without communication between the two servers to share their
information on current leases, when one server is down, any client with a lease
from it will not be able to renew their lease with the other server. Such
communication is the purpose of the "server to server protocol" (see next
question). It is possible that some server vendors have addressed this issue with
their own proprietary server-to-server communication.
20. When will the server to server protocol be defined?
The DHC WG of the IETF is actively investigating the issues in inter-server
communication. The protocol should be defined "soon".
21.Where is DHCP defined?
In Internet RFCs.
22. Can DHCP support remote access?
PPP has its own non-DHCP way in which communications servers can hand
clients an IP address called IPCP (IP Control Protocol) but doesn't have the same
flexibility as DHCP or BOOTP in handing out other parameters. Such a
communications server may support the use of DHCP to acquire the IP addresses
it gives out. This is sometimes called doing DHCP by proxy for the client. I know
that Windows NT's remote access support does this.
A feature of DHCP under development (DHCPinform) is a method by which a
DHCP server can supply parameters to a client that already has an IP number.
With this, a PPP client could get its IP number using IPCP, then get the rest of its
parameters using this feature of DHCP.
SLIP has no standard way in which a server can hand a client an IP address, but
many communications servers support non-standard ways of doing this that can
be utilized by scripts, etc. Thus, like communications servers supporting PPP,
such communications servers could also support the use of DHCP to acquire the
IP addressees to give out.
The DHCP protocol is capable of allocating an IP address to a device without an
IEEE-style MAC address, such as a computer attached through SLIP or PPP, but
to do so, it makes use of a feature which may or may not be supported by the
DHCP server: the ability of the server to use something other than the MAC
address to identify the client. Communications servers that acquire IP numbers
for their clients via DHCP run into the same roadblock in that they have just one
MAC address, but need to acquire more than one IP address. One way such a
communications server can get around this problem is through the use of a set
of unique pseudo-MAC addresses for the purposes of its communications with
the DHCP server. Another way (used by Shiva) is to use a different "client ID
type" for your hardware address. Client ID type 1 means you're using MAC
addresses. However, client ID type 0 means an ASCII string.
23.How can I relay DHCP if my router does not support it?
A server on a net(subnet) can relay DHCP or BOOTP for that net. Microsoft has
software to make Windows NT do this.
24.What is DHCP Spoofing?
Ascend Pipeline ISDN routers (which attach Ethernets to ISDN lines) incorporate
a feature that Ascend calls "DHCP spoofing" which is essentially a tiny server
implementation that hands an IP address to a connecting Windows 95 computer,
with the intention of giving it an IP number during its connection process.
25. How long should a lease be?
A very relevant factor is that the client starts trying to renew the lease when it is
halfway through: thus, for example, with a 4 day lease, the client which has lost
access to its DHCP server has 2 days from when it first tries to renew the lease
until the lease expires and the client must stop using the network. During a 2-
day outage, new users cannot get new leases, but no lease will expire for any
computer turned on at the time that the outage commences.
Another factor is that the longer the lease the longer time it takes for client
configuration changes controlled by DHCP to propogate.
25. How can I control which clients get leases from my server?
There is no ideal answer: you have to give something up or do some extra work.
You can put all your clients on a subnet of your own along with your own
DHCP server.
You can use manual allocation.
Perhaps you can find DHCP server software that allows you to list which
MAC addresses the server will accept. DHCP servers that support roaming
machines may be adapted to such use.
You can use the user class option assuming your clients and server
support it: it will require you to configure each of your clients with a user
class name. You still depend upon the other clients to respect your
wishes.
26. How can I prevent unauthorized laptops from using a network that uses DHCP for dynamic addressing?
This would have to be done using a mechanism other than DHCP. DHCP does not
prevent other clients from using the addresses it is set to hand out nor can it
distinguish between a computer's permanent MAC address and one set by the
computer's user. DHCP can impose no restrictions on what IP address can use a
particular port nor control the IP address used by any client.
27. What features or restrictions can a DHCP server have?
While the DHCP server protocol is designed to support dynamic management of
IP addresses, there is nothing to stop someone from implementing a server that
uses the DHCP protocol, but does not provide that kind of support. In particular,
the maintainer of a BOOTP server-implementation might find it helpful to
enhance their BOOTP server to allow DHCP clients that cannot speak "BOOTP" to
retrieve statically defined addresses via DHCP. The following terminology has
become common to describe three kinds of IP address allocation/management.
These are independent "features": a particular server can offer or not offer any
of them:
Manual allocation: the server's administrator creates a configuration for
the server that includes the MAC address and IP address of each DHCP
client that will be able to get an address: functionally equivalent to
BOOTP though the protocol is incompatible.
Automatic allocation: the server's administrator creates a configuration
for the server that includes only IP addresses, which it gives out to
clients. An IP address, once associated with a MAC address, is
permanently associated with it until the server's administrator intervenes.
Dynamic allocation: like automatic allocation except that the server will
track leases and give IP addresses whose lease has expired to other
DHCP clients.
Other features which a DHCP server may or may not have:
Support for BOOTP clients.
Support for the broadcast bit.
Administrator-settable lease times.
Administrator-settable lease times on manually allocated addresses.
Ability to limit what MAC addresses will be served with dynamic
addresses.
Allows administrator to configure additional DHCP option-types.
Interaction with a DNS server. Note that there are a number of
interactions that one might support and that a standard set & method is
in the works.
Interaction with some other type of name server, e.g. NIS.
Allows manual allocation of two or more alternative IP numbers to a
single MAC address, whose use depends upon the gateway address
through which the request is relayed.
Ability to define the pool/pools of addresses that can be allocated
dynamically. This is pretty obvious, though someone might have a server
that forces the pool to be a whole subnet or network. Ideally, the server
does not force such a pool to consist of contiguous IP addresses.
Ability to associate two or more dynamic address pools on separate IP
networks (or subnets) with a single gateway address. This is the basic
support for "secondary nets", e.g. a router that is acting as a BOOTP
relay for an interface which has addresses for more than one IP network
or subnet.
Ability to configure groups of clients based upon client-supplied user
and/or vendor class. Note: this is a feature that might be used to assign
different client-groups on the same physical LAN to different logical
subnets.
Administrator-settable T1/T2 lengths.
Interaction with another DHCP server. Note that there are a number of
interactions that one might support and that a standard set & method is
in the works.
Use of PING (ICMP Echo Request) to check an address prior to
dynamically allocating it.
Server grace period on lease times.
Ability to force client(s) to get a new address rather than renew.
DHCP Discovery:
The client broadcasts on the local physical subnet to find available servers. Network
administrators can configure a local router to forward DHCP packets to a DHCP server on a
different subnet. This client-implementation creates a UDP packet with the broadcast
destination of 255.255.255.255 or subnet broadcast address and also requests its last-known
IP address (in the example below, 192.168.1.100) although the server may ignore this optional
parameter....
DHCP Offers:
When a DHCP server receives an IP lease request from a client, it extends an IP lease offer.
This is done by reserving an IP address for the client and broadcasting a DHCPOFFER message
across the network. This message contains the client's MAC address, followed by the IP
address that the server is offering, the subnet mask, the lease duration, and the IP address of
the DHCP server making the offer.
The server determines the configuration, based on the client's hardware address as specified in
the CHADDR field. Here the server, 192.168.1.1, specifies the IP address in the YIADDR field.
DHCP Requests:
Whenever a computer comes on line, it checks to see if it currently has an IP address leased. If
it does not, it requests a lease from a DHCP server. Because the client computer does not know
the address of a DHCP server, it uses 0.0.0.0 as its own IP address and 255.255.255.255 as
the destination address. Doing so allows the client to broadcast a DHCPDISCOVER message
across the network. Such a message consists of the client computer's Media Access Control
(MAC) address (the hardware address built into the network card) and its NetBIOS name.
The client selects a configuration out of the DHCP "Offer" packets it has received and
broadcasts it on the local subnet. Again, this client requests the 192.168.1.100 address that
the server specified. In case the client has received multiple offers it specifies the server from
which it has accepted the offer.
DHCP Acknowledgement:
When the DHCP server receives the DHCPREQUEST message from the client, it initiates the
final phase of the configuration process. This acknowledgement phase involves sending a
DHCPACK packet to the client. This packet includes the lease duration and any other
configuration information that the client might have requested. At this point, the TCP/IP
configuration process is complete.
The server acknowledges the request and sends the acknowledgement to the client. The
system as a whole expects the client to configure its network interface with the supplied
options.
FIREWALL
What is a Firewall?
A firewall is a piece of software or hardware that helps screen out hackers, viruses, and worms that try to reach your computer over the Internet. If you are a home user or small-business user, using a firewall is the most effective and important first step you can take to help protect your computer.
Different Types of Firewalls
Different firewalls use different techniques. Most firewalls use two or more of the following techniques:
Packet Filters:
A packet filter looks at each packet that enters or leaves the network and accepts or rejects the packet based on user-defined rules. Packet filtering is fairly effective and transparent, but it is difficult to configure. In addition, it is susceptible to IP spoofing.
Application Gateway:
An application gateway applies security mechanisms to specific programs, such as FTP and Telnet. This technique is very effective, but it can cause performance degradation.
Circuit-layer Gateway:
This technique applies security mechanisms when a Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) connection is established. After the connection has been established, packets can flow between the hosts without any further checking.
Proxy Server:
A proxy server intercepts all messages that enter and leave the network. The proxy server effectively hides the true network addresses.
Application Proxies:
Application proxies have access to the whole range of information in the network stack. This permits the proxies to make decisions based on basic authorization (the source, the destination and the protocol) and also to filter offensive or disallowed commands in the data stream. Application proxies are "stateful," meaning they keep the "state" of connections inherently. The Internet Connection Firewall feature that is included in Windows XP is a "stateful" firewall, as well as, the Windows Firewall. The Windows Firewall is included with Windows XP Service Pack 2 (SP2).
What does a firewall do?
A firewall examines all traffic routed between the two networks to see if it meets certain criteria. If it does, it is routed between the networks, otherwise it is stopped. A firewall filters both inbound and outbound traffic. It can also manage public access to private networked resources such as host applications. It can be used to log all attempts to enter the private network and trigger alarms when hostile or unauthorized entry is attempted. Firewalls can filter packets based on their source and destination addresses and port numbers. This is known as address filtering. Firewalls can also filter specific types of network traffic. This is also known as protocol filtering because the decision to forward or reject traffic is dependant upon the protocol used, for example HTTP, ftp or telnet. Firewalls can also filter traffic by packet attribute or state.
What can't a firewall do?
A firewall cannot prevent individual users with modems from dialling into or out of the network, bypassing the firewall altogether. Employee misconduct or carelessness cannot be controlled by firewalls. Policies involving the use and misuse of passwords and user accounts must be strictly enforced. These are management issues that should be raised during the planning of any security policy but that cannot be solved with firewalls alone.
The arrest of the Phonemasters cracker ring brought these security issues to light. Although they were accused of breaking into information systems run by AT&T Corp., British Telecommunications Inc., GTE Corp., MCI WorldCom, Southwestern Bell, and Sprint Corp, the group did not use any high tech methods such as IP spoofing (see question 10). They used a combination of social engineering and dumpster diving. Social engineering involves skills not unlike those of a confidence trickster. People are tricked into revealing sensitive information. Dumpster diving or garbology, as the name suggests, is just plain old looking through company trash. Firewalls cannot be effective against either of these techniques.
Who needs a firewall?
Anyone who is responsible for a private network that is connected to a public network needs firewall protection. Furthermore, anyone who connects so much as a single computer to the Internet via modem should have personal firewall software. Many dial-up Internet users believe that anonymity will protect them. They feel that no malicious intruder would be motivated to break into their computer. Dial up users who have been victims of malicious attacks and who have lost entire days of work, perhaps having to reinstall their operating system, know that this is not true. Irresponsible pranksters can use automated robots to scan random IP addresses and attack whenever the opportunity presents itself.
How does a firewall work?
There are two access denial methodologies used by firewalls. A firewall may allow all traffic through unless it meets certain criteria, or it may deny all traffic unless it meets certain criteria. The type of criteria used to determine whether traffic should be allowed through varies from one type of firewall to another. Firewalls may be concerned with the type of traffic, or with source or destination addresses and ports. They may also use complex rule bases that analyse the application data to determine if the traffic should be allowed through. How a firewall determines what traffic to let through depends on which network layer it operates at. A discussion on network layers and architecture follows.
Desktop Firewall
Any software installed on an operating system to protect a single computer, like the one included with Windows XP, is called a desktop or personal firewall. This type of firewall is designed to protect a single desktop computer. This is a great protection mechanism if the network firewall is compromised.
Software Firewall
This type of firewall is a software package installed on a server operating system which turns the server into a full fledged firewall. Many people do not consider this the most secure type of firewall as you have the inherit security issues of the underlying operating system. This type of firewall is often used as an application firewall. This means the firewall is optimized to protect applications such as web application and email servers. Software firewalls have complex filters to inspect the content of the network traffic to insure that type of traffic is properly formatted. This type of firewall is usually (but not always) behind hardware firewalls (explanation to follow).
Hardware Firewall
A hardware firewall is a dedicated hardware device with a proprietary operating system or a stripped down operating system core. These firewalls include network routers with additional firewall capabilities. These firewalls are designed to handle large amounts of network traffic. Hardware firewalls are often placed on the perimeter of the network to filter the internet noise and only allow pre-determined traffic into the network. Sometimes hardware firewalls are used in conjunction with software firewalls so the hardware firewall filters out the traffic and the software firewall inspects the network traffic. When hardware firewalls are bombarded with bogus network traffic they drop the unwanted traffic only letting in the right traffic. This not only protects the software firewall but allows the software firewall only has to inspect proper network traffic thus the combination optimizes the network throughput.
Network-Level Firewalls
The first generation of firewalls (c. 1988) worked at the network level by inspecting packet headers and filtering traffic based on the IP address of the source and the destination, the port and the service. Some of these primeval security applications could also filter packets based on protocols, the domain name of the source and a few other attributes.
Network-level firewalls are fast, and today you'll find them built into most network appliances, particularly routers. These firewalls, however, don't support sophisticated rule-based models. They don’t understand languages like HTML and XML, and they are capable of decoding SSL-encrypted packets to examine their content. As a result, they can’t validate user inputs or detect maliciously modified parameters in an URL request. This leaves your network vulnerable to a number of serious threats.
Circuit-Level Firewalls
These applications, which represent the second-generation of firewall technology, monitor TCP handshaking between packets to make sure a session is legitimate. Traffic is filtered based on specified session rules and may be restricted to recognized computers only. Circuit-level firewalls hide the network itself from the outside, which is useful for denying access to intruders. But they don't filter individual packets.
Application-Level Firewalls
Recently, application-level firewalls (sometimes called proxies) have been looking more deeply into the application data going through their filters. By considering the context of client requests and application responses, these firewalls attempt to enforce correct application behavior, block malicious activity and help organizations ensure the safety of sensitive information and systems. They can log user activity too. Application-level filtering may include protection against spam and viruses as well, and be able to block undesirable Web sites based on content rather than just their IP address.
If that sounds too good to be true, it is. The downside to deep packet inspection is that the more closely a firewall examines network data flow, the longer it takes, and the heavier hit your network performance will sustain. This is why the highest-end security appliances include lots of RAM to speed packet processing. And of course you'll pay for the added chips.
Stateful Multi-level Firewalls
SML vendors claim that their products deploy the best features of the other three firewall types. They filter packets at the network level and they recognize and process application-level data, but since they don't employ proxies, they deliver reasonably good performance in spite of the deep packet analysis. On the downside, they are not cheap, and they can be difficult to configure and administer.
RAID
What is RAID?
In 1987, Patterson, Gibson and Katz at the University of California Berkeley, published a paper entitled "A Case for Redundant Arrays of Inexpensive Disks (RAID)" . This paper described various types of disk arrays, referred to by the acronym RAID. The basic idea of RAID was to combine multiple small, inexpensive disk drives into an array of disk drives which yields performance exceeding that of a Single Large Expensive Drive (SLED). Additionally, this array of drives appears to the computer as a single logical storage unit or drive.
RAID stands for Redundant Array of Independent Disks and it basically involves
combining two or more drives together to improve the performance and the fault tolerance.
Combining two or more drives together also offers improved reliability and larger data volume sizes.A RAID distributes the data across several disks and the operating system considers this array as a single disk.
Using Multiple Hard Drives for Performance and Reliability.
Types of RAID :
RAID 0 - Striping:
It is the Stripped Disk Array with no fault tolerance and it requires at least 2 drives to be implemented. Due to no redundancy feature, RAID 0 is considered to be the lowest ranked RAID level. Striped data mapping technique is implemented for high performance at low cost.
The I/O performance is also improved as it is loaded across many channels. Regeneration, Rebuilding and functional redundancy are some salient features of RAID 0.
Raid1: Disk mirroring is the basic function occurs.
1. It creats exact copy of one physical harddisk to another.
2. It uses one controller
3. If one drive fails system will boot with other drive.
4. slow performance.
5. Increased cost every mirror must be seperate physical device thus you must purchase twice the storage capacity.
6. no protection from controller failure.: if controller failure , the mirrored drives as just inaccessible.
RAID 0+1:
It is the RAID array providing high data transference performance with at least 4 disks needed to implement the RAID 0+1 level.
It's a unique combination of stripping and mirroring with all the best features of RAID 0 and RAID 1 included such as fast data access and fault tolerance at single drive level. The multiple stripe segments have added high I/O rates to the RAID performance and it is the best solution for maximum reliability.
RAID 2 (ECC):
It is the combination of Inherently Parallel Mapping and Protection RAID array. It's also known as ECC RAID because each data word bit is written to data disk which is verified for correct data or correct disk error when the RAID disk is read. Due to special disk features required, RAID 2 is not very popular among the corporate data storage masses, despite the extremely high data transference rates.
RAID 3:
RAID 3 works on the Parallel Transfer with Parity technique. The least number of disks required to implement the RAID array is 3 disks.
In the RAID 3, data blocks are striped and written on data drives and then the stripe parity is generated, saved and afterwards used to verify the disk reads. Read and write data transfer rate is very high in RAID 3 array and disk failure causes insignificant effects on the overall performance of the RAID.
RAID 4:
RAID 4 requires a minimum of 3 drives to be implemented. It is composed of independent disks with shared parity to protect the data. Data transaction rate for Read is exceptionally high and highly aggregated. Similarly, the low ratio of parity disks to data disks indicates
high efficiency.
RAID 5:
RAIDS 5 is Independent Distributed parity block of data disks with a minimum requirement of at least 3 drives to be implemented and N-1 array capacity. It helps in reducing the write inherence found in RAID 4. RAID 5 array offers highest data transaction Read rate, medium data transaction Write rate and good cumulative transfer rate.
Raid 5: Disk stripping with parity.It is completely Software based and higly secured technology.
1. Raid 5 is in-expensive, but very convinient.
2.The parity information is stored distributed in different disk .
3.If one of the disk fails , it is hot swappable.
4.Parity information is stored in other Harddisk is automatically
updated to failed one.
5.If more than one disk fails, it should be restored from backup.
RAID 6:
RAIDS 6 is Independent Data Disk array with Independent Distributed parity. It is known to be an extension of RAID level 5 with extra fault tolerance and distributed parity scheme added. RAID 6 is the best available RAID array for mission critical applications and data storage needs, though the controller design is very complex and overheads are extremely high.
RAID 7:
RAID 7 is the Optimized Asynchrony array for high I/O and data transfer rates and is considered to be the most manageable RAID controller available. The overall write performance is also known to be 50% to 90% better and improved than the single spindle
array levels with no extra data transference required for parity handling. RAID 7 is registered as a standard trademark of Storage Computer Corporation.
RAID 10:
RAID 10 is classified as the futuristic RAID controller with extremely high Reliability and performance embedded in a single RAID controller.
The minimum requirement to form a RAID level 10 controller is 4 data disks. The implementation of RAID 10 is based on a striped array of RAID 1 array segments, with almost the same fault tolerance level as RAID 1. RAID 10 controllers and arrays are suitable for
uncompromising availability and extremely high throughput required systems an environment.
With all the significant RAID levels discussed here briefly, another important point to add is that whichever level of RAID is used regular and consistent data backup maintenance using tape storage is must as the regular tape storage is best media to recover from lost data scene.
RAID 1:
RAID 1 uses mirroring to write the data to the drives. It also offers fault tolerance from the disk errors and the array continues to operate efficiently as long as at least one drive is functioning properly.
The trade-off associated with the RAID 1 level is the cost required to purchase the additional disks to store data.
RAID 2:
It uses Hamming Codes for error correction. In RAID 2, the disks are synchronized and they're striped in very small stripes. It requires multiple parity disks.
RAID 3:
This level uses a dedicated parity disk instead of rotated parity stripes and offers improved performance and fault tolerance.
The benefit of the dedicated parity disk is that the operation continues without parity if the parity drive stops working during the operation.
RAID 4:
It is similar to RAID 3 but it does block-level stripping instead of the byte-level stripping and as a result, a single file can be stored in blocks. RAID 4 allows multiple I/O requests in parallel but the data transfer speed will be less.
Block level parity is used to perform the error detection.
RAID 5:
RAID 5 uses block-level stripping with distributed parity and it requires all drives but one to be present to operate correctly.
The reads are calculated from the distributed parity upon the drive failure and the entire array is not destroyed by a single drive failure.
However, the array will lose some data in the event of the second drive failure.
The above standard RAID levels can be combined together in different ways to create Nested RAID Levels which offer improved performance.
Some of the known Nested RAID Levels are -
RAID 0+1
RAID 1+0
RAID 3+0
RAID 0+3
RAID 10+0
RAID 5+0
RAID 6+0
Hardware RAID
A conventional Hardware RAID consists of a RAID controller that is installed into the PC or server, and the array drives are connected to it.
In high end external intelligent RAID controllers, the RAID controller is removed completely from the system to a separate box. Within the box the RAID controller manages the drives in the array, typically using SCSI, and then presents the logical drives of the array over a standard interface (again, typically a variant of SCSI) to the server using the array.
Software RAID:
In software RAID a software does the work of RAID controller in place of a hardware. Instead of using dedicated hardware controllers or intelligent boxes, we use a particular software that manages and implements RAID array with a system software routine.
Comparing Hardware RAID & Software RAID
Portability
OS Portability
Software RAID is not usable across operating systems. So you cannot, for example, use two RAID disks configured in Linux with Windows XP and vice versa. This is big issue for dual booting systems where you will either have to provide a non-RAID disk for data sharing between the two operating system or use hardware RAID instead.
As you know, dual booting is mostly obsolete these days as you can run multiple operating systems on the same machine using virtualization software like vmware & xen.
Hardware Portability
Software RAID
In Linux you can mirror two disks using RAID-1, including the boot partition. If for any reason the hardware goes bad, you can simply take the harddisk to a different machine and it will just run fine on the new hardware. Also with a RAID-1 array, each of the harddisk will have full copy of the operating system and data, effectively providing you with two backups, each of which can be run from a different hardware.
Unfortunately in Windows it is not so easy to switch a operating systrem from one hardware to another, but that is the story of priprietary licenses and we will keep it for another day.
Hardware RAID
Hardware RAID is not so portable. You cannot just swap the hardware to a different machine and hope it will work. You have to find a Motherboard which is compatible with your RAID controller card; otherwise you can kiss your data goodbye. Also there is a bigger issue of problem with the RAID controller itself. If it fails and you cannot get the same controller from the market (and it has probably become obsolete by then), then again you can kiss your data goodbye.
Easy & Speedy Recovery
It may seem trivial but trust me, for a busy and loaded server, an easy and speedy recovery, that too inside the operating system without having to reboot is what one can dream of. Imagine if during the peak hours, your RAID system crashes and you are forced to reboot the machine to make changes to it to restore your data! Software RAID's like in Linux, not only continues working even when the hardware has failed, but also starts restoring the RAID array, should any spare disk be available. All of these happens in the background and without affecting your users. This is where software RAID shines brilliantly.
System Performance
Software RAID uses the CPU to do the work of the RAID controller. This is why high-end hardware RAID controller outperforms software RAID, especially for RAID-5, because it has a high powered dedicated processor. However for low end hardware RAID, the difference may be neglible to non-existent. In fact it is possible for the software RAID perform better than low end hardware RAID controller simply because today's desktop's and workstations are powered by very powerful processors and the task is trivial to them.
Support for RAID Standards
High-end Hardware RAID may be slightly more versatile than Software RAID in support for various RAID levels. Software RAID is normally support levels 0, 1, 5 and 10 (which is a combination of RAID 0 and RAID 1) whereas many Hardware RAID controller can also support esoteric RAID levels such as RAID 3 or RAID 1+0. But frankly who uses them?
Cost
This is where software RAID again scores over hardware RAID. Software RAID is free. Hardware RAID is moderate to high priced and can put a strain on your budget if deployed widely.
But over the years the cost of hardware RAID has come down exponentially. So it may not be too far when more affordable RAID-5 cards will be built-in on newer motherboards.
Future Proof
Gone are the days when we could associate software RAIDs with bugs and OS problems. Nowadays software RAIDs are almost flawless. We are using software RAID in linux operating system for several years and haven't experienced any problem whatsoever. On the contrary, hardware RAID has a single point of failure and that is its hardware controller. If it crashes then your only option is to find another equivalent RAID controller from the market; by this time the model may become obsolete and you may not even find anything compatible. You are as such faced with the haunting prospect of losing all your data, should the RAID controller fail. Software RAID will never become obsolete and will continue to get updated with updated versions of your operating system.
Why Use RAID? Benefits and Costs, Tradeoffs and Limitations
RAID offers many advantages over the use of single hard disks, but it is clearly not for everyone. The potential for increased capacity, performance and reliability are attractive, but they come with real costs. Nothing in life is free. In this section I take an overview look at RAID, to help explain its benefits, costs, tradeoffs and limitations. This should give you a better idea if RAID is for you, and help you to understand what RAID can do--and what it can't do.
As you read on, it's essential to keep in mind that with RAID, it's definitely the case that "the devil is in the details". Most common blanket statements made about RAID like "RAID improves availability" or "RAID is for companies that need fast database service" or "RAID level 5 is better than RAID level 0" are only true at best part of the time. In almost every case, it depends. Usually, what RAID is and what it does for you depends on what type you choose and how you implement and manage it. For example, for some applications RAID 5 is better than RAID 0; for others, RAID 0 is vastly superior to RAID 5! There are situations where a RAID design, hardware and software that would normally result in high reliability could result instead in disaster if they are not properly controlled.
RAID Benefits
Alright, let's take a look at the good stuff first. :^) RAID really does offer a wealth of significant advantages that would be attractive to almost any serious PC user . (Unfortunately, there are still those pesky costs ,tradeoffs and limitations to be dealt with... :^) ) The degree that you realize the various benefits below does depend on the exact type of RAID that is set up and how you do it, but you are always going to get some combination of the following:
Higher Data Security: Through the use of redundancy, most RAID levels provide protection for the data stored on the array. This means that the data on the array can withstand even the complete failure of one hard disk (or sometimes more) without any data loss, and without requiring any data to be restored from backup. This security feature is a key benefit of RAID and probably the aspect that drives the creation of more RAID arrays than any other. All RAID levels provide some degree of data protection , depending on the exact implementation, except RAID level 0 .
Fault Tolerance: RAID implementations that include redundancy provide
a much more reliable overall storage subsystem than can be achieved by a single disk.
This means there is a lower chance of the storage subsystem as a whole failing
due to hardware failures. (At the same time though, the added hardware used in
RAID means the chances of having a hardware problem of some sort
with an individual component, even if it doesn't take down the storage subsystem, is increased
Improved Availability: Availability refers to access to data. Good RAID systems improve availability both by providing fault tolerance and by providing special features that allow for recovery from hardware faults without disruption.
Increased, Integrated Capacity: By turning a number of smaller drives into a larger array,
you add their capacity together (though a percentage of total capacity is lost to overhead or
redundancy in most implementations). This facilitates applications that require large
amounts of contiguous disk space, and also makes disk space management simpler.
Let's suppose you need 300 GB of space for a large database. Unfortunately, no hard disk
manufacturer makes a drive nearly that large. You could put five 72 GB drives into the system,
but then you'd have to find some way to split the database into five pieces, and you'd be
stuck with trying to remember what was were. Instead, you could set up a RAID 0 array
containing those five 72 GB hard disks; this will appear to the operating system as a single,
360 GB hard disk! All RAID implementations provide this "combining" benefit, though the
ones that include redundancy of course "waste" some of the space on that redundant information.
Improved Performance: Last, but certainly not least, RAID systems improve performance by allowing the controller to exploit the capabilities of multiple hard disks to get around performance-limiting mechanical issues that plague individual hard disks. Different RAID implementations improve performance in different ways and to different degrees, but all improve it in some way.
Server 2003 Interview Question Answers
Posted by Anuj Sharma on August 11th, 2010 | No Comments
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1. What is the different between Workgroup and Domain?
A workgroup is an interconnection of a number of systems that share resources such as files &printers without a dedicated server .Each workgroup maintains a local database for user accounts, security etc. A domain, on the otherhand is an interconnection of systems that share resources with one or more dedicated server, which can be used to control security and permissions for all users in the domain. Domain maintains a centralized database and hence a centralized management of user accounts, policies etc are established. If you have a user account on domain then you can log on to any system without user account on that particular system.
2. How will assign Local Administrator rights for domain user?
To assign a domain user with local administrative right in any client of domain we should log in to the respected client system then, Start->control panel->user accounts->give username, password and name of domain->add->advanced->locations->find now->select others(in that select administrator user)->ok->next->ok.
3. How will you restrict user logon timing in domain?
Start->dsa.msc->double click on users->right click on any users->properties->click on account->click on logon hours->logon denied->select time (by dragging mouse)->click on logon permission->ok.
4. What is the purpose of sysvol?
The sysvol folder stores the server’s copy of the domain’s public files. The contents such as group policy, users etc of the sysvol folder are replicated to all domain controllers in the domain. The sysvol folder must be located on an NTFS volume.
5. What is OU? Explain its Uses.
An object is a set of attributes that represents a network resource, say a user, a computer, a group policy, etc and object attributes are characteristics of that object stored in the directory. Organizational units act as a container for objects. Objects can be arranged according to security and administrative requirement in an organization. You can easily manage and locate objects after arranging them into organizational units. Administrator can delegate the authority to manage different organizational units and it can be nested to other organizational units. Create an OU if you want to:
* Create a company’s structure and organization within a domain – Without OUs, all users are maintained and
displayed in a single list, the Users container, regardless of a user’s department, location, or role.
* Delegate administrative control – Grant administrative permissions to users or groups of users at the OU level.
* Accommodate potential changes in a company’s organizational structure – Users can easily be reorganized between
OUs, while reorganizing users between domains generally requires more time and effort.
* Group objects with similar network resources – This way it is easy to perform any administrative tasks. For example,
all user accounts for temporary employees can be grouped in an OU.
* Restrict visibility – Users can view only the objects for which they have access.
6. Explain different edition of windows 2003 Server?
*Windows Server 2003, Web Edition :- is mainly for building and hosting Web applications, Web pages, and XML Web Services.
* Windows Server 2003, Standard Edition :- is aimed towards small to medium sized businesses. Flexible yet versatile, Standard Edition supports file and printer sharing, offers secure Internet connectivity, and allows centralized desktop application deployment
* Windows Server 2003, Enterprise Edition :- is aimed towards medium to large businesses. It is a full-function server operating system that supports up to eight processors and provides enterprise-class features such as eight-node clustering using Microsoft Cluster Server (MSCS) software and support for up to 32 GB of memory.
* Windows Server 2003, Datacenter Edition:- is the flagship of the Windows Server line and designed for immense infrastructures demanding high security and reliability.
* Windows Server 2003, Compute Cluster Edition:- is designed for working with the most difficult computing problems that would require high performance computing clusters.
* Windows Storage Server 2003:- is optimised to provide dedicated file and print sharing services. It is only available through OEMs when purchased pre-configured with network attached storage devices.
7. What is DNS Server?
Domain Name System (or Service or Server), a service that resolves domain names into IP addresses and vice versa. Because domain names are alphabetic, they’re easier to remember.The Internet however, is really based on ip addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.example.com might translate to 198.105.232.4.
The DNS system is, in fact, its own network. If one DNS server doesn’t know how to translate a particular domain name, it asks another one, and so on, until the correct IP address is returned.
8. Why DNS server is required for Active Directory?
The key reason for integrating DNS and AD is efficiency. This is particularly true where you have lots of replication traffic. You can’t resolve host names. You can’t find services, like a domain controller.
9. What is the Purpose of A and PTR Record?
A (Host) record is used to resolve name to ip address while PTR (pointer) record is used to resolve ip address to name.
10. What is the purpose of DHCP Server?
A DHCP server is the server that is responsible for assigning unique IP address to the computers on a network. No two computers (actually, no two network cards1 [even if two are in one computer]) can have the same IP address on a network at the same time or there will be conflicts. To that end, DHCP servers will take a request from a computer that has just been added (or is renewing) to the network and assign it a unique IP address that is available. These assignments typically only last for a limited time (an hour to a week usually) and so you are never guaranteed that the IP address for a particular computer will remain the same when using a DHCP (some DHCP servers allow you to specify that a computer gets the same address all the time however).
11. Explain about Group Scopes?
A DHCP scope is a valid range of IP addresses which are available for assignments or lease to client computers on a particular subnet. In a DHCP server, you configure a scope to determine the address pool of ip which the server can provide to DHCP clients.
Scopes determine which IP addresses are provided to the clients. Scopes should be defined and activated before DHCP clients use the DHCP server for its dynamic IP configuration. You can configure as many scopes on a DHCP server as is required in your network environment
12. How will you backup DNS Server?
If you are using Active Directory-integrated DNS, then your DNS information is stored in Active Directory itself, and you’ll need to back up the entire system state. If not, however, The Backup directory in the %SystemRoot%\System32\Dns folder contains backup information for the DNS configuration and the DNS database.
13. How will backup DHCP Server?
The Backup directory in the %SystemRoot%\System32\DHCP folder contains backup information for the DHCP configuration and the DHCP database. By default, the DHCP database is backed up every 60 minutes automatically. To manually back up the DHCP database at any time, follow these steps:
1. In the DHCP console, right-click the server you want to back up, and then click Backup.
2. In the Browse For Folder dialog box, select the folder that will contain the backup DHCP database, and then click OK.
14. Explain APIPA.
A Windows-based computer that is configured to use DHCP can automatically assign itself an Internet Protocol (IP) address if a DHCP server is not available or does not exist. The Internet Assigned Numbers Authority (IANA) has reserved 169.254.0.0-169.254.255.255 for Automatic Private IP Addressing(APIPA).
15. Explain about AD Database.
Windows 2003 Active Directory data store, the actual database file, is %SystemRoot%\ntds\NTDS.DIT. The ntds.dit file is the heart of Active Directory including user accounts. Active Directory’s database engine is the Extensible Storage Engine ( ESE ) which is based on the Jet database used by Exchange 5.5 and WINS. The ESE has the capability to grow to 16 terabytes which would be large enough for 10 million objects.Only the Jet database can manipulate information within the AD datastore.
16. Explain about Group Policy.
Group policies are used by administrators to configure and control user environment settings. Group Policy Objects (GPOs) are used to configure group policies which are applied to sites, domains, and organizational units (OUs). Group policy may be blocked or set so it cannot be overridden. The default is for subobjects to inherit the policy of their parents. There is a maximum of 1000 applicable group policies.
Group policies are linked to domains, organizational units, or sites in Active Directory. A policy must be linked to a container object in Active Directory to be effective. They are stored in any domain for storage but can be linked to other domains to make them effective there also. The policy must be linked to the container (site, domain, or OU) that it is stored in to be effective in that container. One policy object can be linked to several containers. Several policy objects can be linked to one container.
17. What is the default time for group policy refresh interval time?
The default refresh interval for policies is 90 minutes. The default refresh interval for domain controllers is 5 minutes. Group policy object’s group policy refresh intervals may be changed in the group policy object.
18. Explain Hidden Share.
Using hidden shares on your network is useful if you do not want a shared folder or drive on the network to be easily accessible. Hidden shares can add another layer of protection for shared files against unauthorized people connecting to your network. Using hidden shares helps eliminate the chance for people to guess your password (or be logged into an authorized Windows account) and then receive access to the shared resource.
Windows automatically shares hard drives by default for administrative purposes. They are hidden shares named with the drive letter followed by a dollar sign (e.g., C$) and commented as Default Share. Thus, certain networking and administrator functions and applications can work properly. Not that preventing Windows from creating these hidden or administrative shares by default each time your computer boots up takes a registry change.
19. What ports are used by DHCP and the DHCP clients?
Requests are on UDP port 68, Server replies on UDP 67.
20. How do I configure a client machine to use a specific IP Address?
Reservation using mac address in DHCP.
21. Name 3 benefits of using AD-integrated zones.
1. We can give easy name resolution to your clients.
2. By creating AD- integrated zone you can also trace hacker and spammer by creating reverse zone.
3. AD integrated zoned all for incremental zone transfers which on transfer changes and not the entire zone. This reduces zone transfer traffic.
4. AD Integrated zones support both secure and dynamic updates.
5. AD integrated zones are stored as part of the active directory and support domain-wide or forest-wide replication through application partitions in AD.
22. How do you backup & Restore AD?
You can backup Active Directory by using the NTBACKUP tool that comes built-in with Windows Server 2003. Backing up the Active Directory is done on one or more of your Active Directory domain Controllers, and is performed by backing up the System State on those servers. The System State contains the local Registry, COM+ Class Registration Database, the System Boot Files, certificates from Certificate Server (if it’s installed), Cluster database (if it’s installed), NTDS.DIT, and the SYSVOL folder. the tombstone is 60 days (Windows 2000/2003 DCs), or 180 days (Windows Server 2003 SP1 DCs).
You can use one of the three methods to restore Active Directory from backup media: Primary Restore, Normal Restore (i.e. Non Authoritative), and Authoritative Restore.
Primary Restore: This method rebuilds the first domain controller in a domain when there is no other way to rebuild the domain. Perform a primary restore only when all the domain controllers in the domain are lost, and you want to rebuild the domain from the backup. Members of the Administrators group can perform the primary restore on local computer. On a domain controller, only members of the Domain Admins group can perform this restore.
Normal Restore: This method reinstates the Active Directory data to the state before the backup, and then updates the data through the normal replication process. Perform a normal restore for a single domain controller to a previously known good state.
Authoritative Restore: You perform this method in tandem with a normal restore. An authoritative restore marks specific data as current and prevents the replication from overwriting that data. The authoritative data is then replicated through the domain. Perform an authoritative restore for individual object in a domain that has multiple domain controllers. When you perform an authoritative restore, you lose all changes to the restore object that occurred after the backup. You need to use the NTDSUTIL command line utility to perform an authoritative restore. You need to use it in order to mark Active Directory objects as authoritative, so that they receive a higher version recently changed data on other domain controllers does not overwrite System State data during replication.
23. How do you change the DS Restore admin password?
Microsoft Windows 2000 uses the Setpwd utility to reset the DS Restore Mode password. In Microsoft Windows Server 2003, that functionality has been integrated into the NTDSUTIL tool. Note that you cannot use the procedure if the target server is running in DSRM.
24. How can you forcibly remove AD from a server?
In run use the command ->dcpromo /forceremoval
25. What is the SYSVOL folder?
The sysvol folder stores the server’s copy of the domain’s public files. The contents such as group policy, users etc of the sysvol folder are replicated to all domain controllers in the domain. The sysvol folder must be located on an NTFS volume
26. What is the entire problem if DNS Server fails?
If your DNS server fails, you can’t resolve host names. You can’t resolve domain controller IP Address.
27. How can you restrict running certain applications on a machine?
The Group Policy Object Editor and the Software Restriction Policies extension of Group Policy Object Editor are used to restrict running certain applications on a machine. For Windows XP computers that are not participating in a domain, you can use the Local Security Settings snap-in to access Software Restriction Policies.
28. What can you do to promote a server to DC?
Start->Run->DCPROMO
29. How will map a folder through AD?
Navigate domain user properties->give path in profile tab in the format \\servername\sharename.
30. Explain Quotas.
Disk Quota is a feature or service of NTFS which helps to restrict or manage the disk usage from the normal user. It can be implemented per user user per volume basis.By default it is disabled. Administrative privilege is required to perform the task. In 2003server we can control only drive but in 2008server we can establish quota in folder level.
31. Explain Backup Methodology.
The different types of backup methodologies are:
* Normal Backup:-This is default backup in which all files are backed up even if it was backed up before.
*Incremental Backup:-In this type of backup only the files that haven’t been backed up are taken care of or backed up.
*Differential Backup:-This backup is similar to incremental backup because it does not take backup of those files backed up by normal
backup but different from incremental because it will take backup of differentially backed up files at next time of differential backup.
*Copy Backup:-This type of backup is which is used during system state backup and asr backup. It is used in special conditions only.
*Daily Backup:-This type of backup takes backup of only those files that are created on that particular day.
*System Backup:-This type of backup takes backup of files namely, Boot file, COM+Class Registry, Registry. But in server it takes
backup of ads.
*ASR Backup:-This type of backup takes backup of entire boot partition including OS and user data. This should be the last
troubleshooting method to recover an os from disaster.
32. Explain how to publish printer through AD.
The group policy setting ‘Automatically publish new printers in AD’ when disabled, prevents the Add Printer Wizard from automatically publishing shared printers. In addition, Group policy setting ‘Allow printers to be published’ should be enabled(default) for printers to be published on that computers.
33. Explain the functionality of FTP Server?
The FTP server is to accept incoming FTP requests. Copy or move the files that you want to make available to the FTP publishing folder for access. The default folder is drive:\Inetpub\Ftproot, where drive is the drive on which IIS is installed
In the client-server model, a file server is a computer responsible for the central storage and management of data files so that other computers on the same network can access the files. A file server allows users to share information over a network without having to physically transfer files by floppy diskette or some other external storage device.
34. Specify the Port Number for AD, DNS, DHCP, HTTP, HTTPS, SMTP, POP3 & FTP
AD- uses LDAP Udp 389 and UDP 135,DNS- 53,DHCP-67,68,HTTP-80,HTTPS-,SMTP-25,POP3-110 & FTP-20,21.
35. Explain Virtual Directory in IIS?
A virtual server can have one home directory and any number of other publishing directories. These other publishing directories are referred to as virtual directories.
36. What is Exclusion Range in DHCP Server?
Exclusion Range is used to reserve a bank of ip addresses so computer that require only static ip address such as DNS servers, legacy printers can use reserved assigned addresses .These are not assigned by DHCP server.
37. Explain SOA Record.
Start Of Authority(SOA) Records indicate that NameServer is authoritative server for the domain.
INTERVIEW QUESTIONS HARDWARE
Posted by Anuj Sharma on August 17th, 2010 | No Comments
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1.What is the difference between Windows XP Professional Edition and Windows XP Home Edition?
Although the XP Pro and Home Editions share the same common core code, they don’t have the same features. The right version for you depends on the functionality you need.
Backup—XP Pro has the standard Win2K backup program; XP Home has no backup program.
Dynamic Disks—XP Pro supports dynamic disks; XP Home doesn’t.
IIS—XP Pro includes IIS; XP Home doesn’t.
Encrypted File System (EFS)—EFS debuted in Win2K and lets you encrypt files on an NTFS partition, a very useful feature for mobile machines. XP Pro includes EFS; XP Home doesn’t.
Multiprocessor—XP Pro supports up to two processors; XP Home supports only one (as did Windows Me/Win98).
Remote Assistance—Both editions support Remote Assistance, which lets someone from a Help desk connect to the client desktop to troubleshoot problems.
Remote Desktop—XP Pro adds to Remote Assistance by letting any machine running a Terminal Services client run one Terminal Services session against an XP Pro machine.
Domain Membership—XP Pro systems can be domain members; XP Home systems can’t, but they can access domain resources.
Group Policy—XP Pro supports group policies; XP Home doesn’t.
IntelliMirror—XP Pro supports IntelliMirror, which includes Microsoft Remote Installation Services (RIS), software deployment, and user setting management; XP Home doesn’t support IntelliMirror.
Upgrade from Windows Me/Win98—Both XP Pro and XP Home support this upgrade.
Upgrade from Win2K/NT—Only XP Pro supports this upgrade.
64-bit Support—Only XP Pro will have a 64-bit version that supports the Itanium systems.
Network Support—XP Pro includes support for Network Monitor, SNMP, IP Security (IPSec), and the Client Services for NetWare (CSNW); XP Home doesn’t.
2. What is the difference between LCD and TFT ?
A liquid crystal display (commonly abbreviated LCD) is a thin, flat display device made up of any number of color or monochrome pixels arrayed in front of a light source or reflector. It is prized by engineers because it uses very small amounts of electric power, and is therefore suitable for use in battery-powered electronic devices.
TFT-LCD (Thin Film Transistor-Liquid Crystal Display) is a variant of Liquid Crystal Display (LCD) which uses Thin-Film Transistor (TFT) technology to improve image quality. TFT LCD is one type of active matrix LCD, though it is usually synonymous with LCD. It is used in both flat panel displays and projectors. In computing, TFT monitors are rapidly displacing competing CRT technology, and are 1commonly available in sizes from 12 to 30 inches.
TFT means Thin Film Transistor Liquid Crystal Display.
What I think you mean is Active and Passive matrix LCD panels. This is where there is a difference in price. A typical active TFT panel capable of resolutions of just 1024×768 is made up of nearly 2.5 million transistors (commonly known as small 3 legged lumps of silicon found in TV’s and most other electronics) eccept in this case, the transistors are etched onto glass, to microscopic precision hence the name “Thin Film Transistor”. A normal LCD basicaly has two layers of glass, one with rows, one with columns, this makes up a grid that can be referenced to control each pixel. The control is done with an IC (integrated circuit or silicon chip) on the LCD’s circuit board/s. TFT’s tend to be quicker ( response time) and nicer to look at in general.
3. How will you install Operating System in more than 50 PC at a time when the all Pcs having same configuration? Create a image of Operating System and the software’s which you want to install on all systems from Symantec ghost and paste or distribute the image on the network. If the pcs are on network you can have RIS or WDS setup. Requirement for clients is they should have network bootable NIC.
4. What is IMAP? How does it work? IMAP is a standard protocol for accessing e-mail from a local server. Using IMAP an email client program can not only retrieve email but can also manipulate message stored on the server, without having to actually retrieve the messages. So messages can be deleted, have their status changed, multiple mail boxes can be managed, etc. IMAP allows for clients / users to read only the header information and then decide if they wish to download the whole msg, useful for blackberry’s etc where data costs money
5. Explain the Windows XP, 2000 and 2003 Boot Process?
following are the booting files for xp ; boot.ini, ntldt, ntdetect.com, ntoskrnl.exe,bootdd.sys, bootsect.dos,hal.dll, system.
First there will be pre- boot sequence, it includes the following
1.POST(power on self test) first check for hardware
2.loads boot.ini, loads mbr.
3.mbr loads active partation
4ntldr loads o.s.
boot process: first loads boot.ini, ntldr will be in boot.ini it loads os. boot.ini shows available os for selection, ntdetect.com check for hardware, ntoskrnl.exe loads drivers for devices.
Booting process are classified into 5 steps.
1.POST
2.The MBR reads the boot sector which is the first sector of the active partition.
3.Ntldr locket path of os from boot.ini
4.Ntldr to run ntdedetect.com to get information about installed hardware.
5.Ntldr reads the registry files then select a hardware profile, control set and loads device drivers.
6.After that Ntoskrnl.exe takes over and starts winlogon.exe which starts lsass.exe
this is the program that display the welcome screen.
6. What is an Open Source OS? List some . Open Source OS is any OS which has the source code with its installation package. This source code is modifiable. If you want your OS to work for you as you want it to, you put your creativity and start redesigning. Get it completed as a new OS and sell it if you are business-minded. An operating system that supports a set of principles and practices on how to write softwares whose source code is openly available.
Examples: Linux versions , UNIX source code is made free and is available for students.
7. What is the difference between unix and windows operating systems?
These both os are multihtread os not multprocessing. Multiprocessing is not possible on single processor system.It’s only possible on multcore or multiprocessor system where more then two process can be scheduled simulteniously .So system having one processor can not do multiprocessing it is only psedo-multiporcessing. Winodow uses Priority based preemptive scheduling while Unix uses Round robin preemtive scheduling. In windows process or thread which has higer priority will take over but this will be the case in Unix.They all will be in Q regardless of their priority.
Window is component based syste.TCP/IP and File systems are the component of the system where Unix is integrated system.
Unix is text based…Windows is GUI based. UNIX is not event driven….Windows is event driven And for God sake both are multithreaded.
8. Why we want Mac address as well as IP address ? Why one address is not enough in net work ?
Mac address is the physical address of a computer. Which is 48 bit.but ip adress is the logical adress assinged to perticular computer .there is two version of ip adress ipv4(32 bit) and ipv6(64 bit).if u type ipconfig/all from the command promt of a computer u can find that both adress.
9. What is ADS & ADSL? ADS stands for Active Directory Services. Generally anything to do with authentication against an Active Directory to workstations or network shares as well as global and security group membership is covered under ADS.
ADSL is short for Asynchronous Digital Subscriber Line. DSL is a very common broadband Internet access method in use all over the place. Asynchronous means that the rate of download is different from, and in my experience always greater than, the rate of upload. It is also possible to have SDSL. That would be Synchronous where the rate of download and upload is the same.
10. Why do we use Subnet mask? What are its uses? Subnet mask is use to isolate the network ID and Host ID. eg- if an IP is:192.168.0.1 then the default subnet is:255.255.255.0 because it is a C Class Address C Class Add. have 3 network octate and 1 host octate i.e.
network ID :192.168.0.0 and host ID : 0.0.0.1
A subnet allows the flow of network traffic between hosts to be segregated based on a network configuration. By organizing hosts into logical groups, subnetting can improve network security and performance. the most recognizable aspect of subnetting is the subnet mask. Like IP addresses, a subnet mask contains four bytes (32 bits) and is often written using the same “dotted-decimal” notation. For example, a very common subnet mask in its binary representation
11111111 11111111 11111111 00000000
is typically shown in the equivalent, more readable form : 255.255.255.0
Subnet mask is 32 bit long TCP/IP address divided in four equal part.It is used for isolation of network address and host address.
11. What is the difference b/w subnet mask and default gateway? Subnet Mask:- the mask is used to detrmine that which part of IP belonged to network or which part belong to host. E.g. if u have a IP 172.16.25.32 and its subnet mask is 255.255.0.0. then the 172.16 is network part , and 25.16 is host part. If subneting is enable then we can use some bit of host part in network .Subnet mask mainly use in subneting. for above example subnet mask is 255.255.255.0 the nwk address become 172.16.25. and the host part is 32.
Default gateway:- For a simple LAN there is no use of default gateway, It is used when network communicate with other network. it is just like a Main gate of home when a person wanna go to outside from home or come inside he can only do the same by main gate. Same Concept used here. In network if the packet have address of same address then switch direct forward the packet to its desired destination. And if packet have another network address it should be come out from Default gate way. Basically it reduces the collision. subnetmask is just used to identify the class of ip address and its is used for subnetting of ip address for eg:-
ipaddress -192.168.1.2
subnetmask- 255.255.255.0
we can find N/W part that is 192.168.1 and Host part that is 2
the class of ip is C
where as default gateway is a ip address given to a router or ASDL modem which is used to communuicate with other N/Ws or internet
12. What is FTP & UDP?What is the different version of IP? FTP or File Transfer Protocol is used to transfer data from one computer to another over the Internet, or through a network
User Datagram Protocol (UDP) is one of the core protocols of the Internet protocol suite. Using UDP, programs on networked computers can send short messages sometimes known as datagrams(using Datagram Sockets) to one another.
ip versions IPv6,IPv4
Questions Regarding Operating Systems
1. What is the difference between x86 and i386 computer? x86 refers to a popular set of instructions most commonly used in processors from Intel, AMD, VIA, and others. It usually implies a binary compatibility with the 32-bit instruction set of the 80386 (a.k.a. i386).
i386 (as eluded to above) is the common name for the Intel386 (or 80386) based PCs. It is sometimes emphasized as x86-32 (for 32-bit) and x86-64 (also called x64 – for 64-bit).
2) Which of the following system software resides in main memory always ? 1. Text editor 2. Assembler 3. Linker 4. Loader? Assembler
3) What is the Difference between NTFS and FAT32?
a) FAT (FAT16 and FAT32) and NTFS are two methods for storing data on a hard drive. The hard drive has to either be formatted using one or the other, or can be converted from one to the other (usually FAT to NTFS) using a system tool
NTFS is a high-performance and self-healing file system proprietary to Windows XP 2000 NT, which supports file-level security, compression and auditing. It also supports large volumes and powerful storage solution such as RAID.
The most important new feature of NTFS is the ability to encrypt files and folders to protect your sensitive data.
b) NTFS 1)allows access local to w2k,w2k3,XP,win NT4 with SP4 & later may get access for somefile.
2)Maximum size of partition is 2 Terabytes & more.
3)Maximum File size is upto 16TB.
4)File & folder Encryption is possible only in NTFS.
FAT 32 1)Fat 32 Allows access to win 95,98,win millenium,win2k,xp on local partition.
2)Maximum size of partition is upto 2 TB.
3)Maximum File size is upto 4 GB.
4)File & folder Encryption is not possible.
4) What is DHCP, How it Works? DHCP stands for dynamic host configuration protocol. What it does is dynamically assign network settings from a server.hence a DHCP configured PC boots, it requests its IP address from the DHCP server. It does this by sending a standardized DHCP broadcast request packet to the DHCP server with a source IP address of 255.255.255.255.
If your DHCP server has more than one interface, you have to add a route for this 255.255.255.255 address so that it knows the interface on which to send the reply; if not, it sends it to the default gateway. (In both of the next two examples, we assume that DHCP requests will be coming in on interface eth0).
5. Can you tell me what causes CMOS checksum errors? . A CMOS checksum is generated by adding all of the bytes (or bits) in the CMOS one after the other. That is, byte one is added to byte 2, byte 3 is added is to the sum of bytes 1 and 2, etc. The carry bits are dropped. The result (checksum) is stored in the CMOS. During the boot-up process or POST (Power-On Self Test) a checksum is generated by the BIOS from the CMOS and compared to the one saved the last time the CMOS Setup was run or the BIOS defaults were loaded. If the two numbers don’t agree it is an indication that the data in the CMOS has been corrupted (one or more bits in the CMOS changed when it/they weren’t supposed to) and a checksum error is issued by the BIOS (“CMOS checksum invalid, ” “CMOS invalid,” and relate error, “CMOS battery low”). Causes include:
A bad battery. A battery that has become discharged (the computer has been off a very long time). A disconnected battery.
Insertion of an expansion board in such a manner (cock-eyed) as to short-out the bus (even if the computer is off, which it should be)
A power surge.
Lightning.
Static electricity.
Grounding the CMOS circuitry.
A bad motherboard.
A bad real-time clock.
6. Every time I boot up my PC the date is 1/1/1998, the time is 00:00. The CMOS battery is coin-shaped… A. Coin-shaped batteries on most motherboareds should be a CR2032. Make sure it is properly installed and + is up. If you have a multimeter or you have a friend who has a multimeter, remove the battery and check the voltage. It should read 3.0 volts when fully charged. If it reads 1.8 volts or higher it is probably OK. Be very careful installing and removing coin-shaped batteries. Most of the battery holders I have seen for these batteries are quite fragile and easily broken. I ease these batteries into the holder with the aid of a “tweaker” (small screw driver).After doing some more research it appears that those blue batteries that were soldered on old motherboards, or at least some of those blue batteries, were Nickel-Cadmium and they were rechargable.
What is the CMOS memory? A. CMOS is an abbreviation for Complementary Metal Oxide Semiconductor. CMOS uses a complimentary arrangement of both NMOS and PMOS, negative and positive Metal Oxide transistor circuits. CMOS memory draws very little current (nano-Amps). Values stored in it can be maintained for very a long period of time while the computer is off with a rechargeable lithium battery. The CMOS memory is used to store system configuration information, such as disk drive parameters, memory configuration, and the date-time, some of which you enter in the CMOS Setup program, . It is used by the Basic Input Output System (BIOS), a program permanently stored in the flash memory on recent motherboards and in read-only memory (ROM) on older motherboards, to configure the computer. The CMOS Setup is part of the BIOS program. The CMOS memory is usually located with the real-time clock in the motherboard chipset or in a separate real-time clock chip. It is located in the chipset on most recent motherboards. For example, the CMOS memory is located in the VT82C596B Southbridge chip in the VIA MVP3C chipset on the Epox MVP3G2 Super7 Motherboard and in the AMD-756 Southbridge in the AMD-750 chipset on the MSI MS-6167 Athlon motherboard.
Q. What causes a computer to reboot itself? A. It could be caused by a lot of things, but it is usually a hardware problem, especially if it occurs randomly. A noisy power supply, loose screw under the motherboard, bad CPU fan, and memory, expansion boards, socketed chips, and cables that are not fully seated are among the common causes.
Q. During bootup my computer hangs at “Verifying DMI pool data.” What is it and how do I fix it?
A. DMI or DesktopManagement Interface (pdf) is a layer of abstraction between system components and the software that manages them. The System Management BIOS (SMBIOS) is an extension of the Basic Input Output System (BIOS) that formulates and delivers this information to the operating system. The pool data is the information. In short, when the BIOS is “Verifying DMI pool data” it is verifying the table of data it sends to the operating system (Windows, etc.). If it isn’t sucessful, it should return an error. Wait a reasonable period of time for it to finish. It may make take some time or it may be stuck. Possible fixes:
1. If you changed the hardware just before this problem occurred (e.g., installed a new hard disk drive), unchange it.
2. If you installed a new hard disk drive, set the motherboard CMOS Setup to Auto for the drive type. You may have to disconnect the drive first.
3. Enable “Reset Configuration Data” (may be “Force Update ESCD” in some CMOS Setuups) in the motherboard CMOS Setup PNP/PCI configuration. (Rebooting will automatically disabled it after it has done its thing.)
4. The CMOS may be corrupted. Clear it.
5. Disconnect all drives not required to boot the computer. If this fixes it, reconnect one at time.
6. The floppy drive may be bad or not connected properly.
7. Reseat all expansion boards.
8. Pull all boards not required to boot the computer.
Q. How can I determine where and how the various front panel connectors (Power-on, hard disk LED, speaker, etc.) connect to the header(s) on my motherboard without the motherboard documentation or clear labeling?
A. You can plug LEDs in backwards and it won’t hurt them or the motherboard. Switches do not have a polarity and can be plugged-in either way. The speaker can be plugged-in either way. It has two wires that usually connect to a four-wire plug. You can plug a switch, which is not closed (most aren’t except, possibly, the key lock on older cases), into a LED connection on the motherboard and it won’t hurt the motherboard (or switch). Do not plug a LED into a switch header on a motherboard or a closed (short) switch into a LED header on the motherboard. I generally start with the Power on switch (ATX motherboard), and then the speaker, and follow with the Power on LED. The Power on LED usually plugs into a five-pin header or a group of five pins on a header with the keylock. Keep plugging it in the four possible positions, backward and forwards, until it lights. The key lock (if it isn’t on a five-pin plug with the Power on) goes into the remaining two pins. You can do this with the computer on. Follow with the reset switch and test. Next, hunt for the HD LED like the Power on, using the Reset switch to boot the computer and light the LED… There are still Turbo LEDs and Switches in the world and some motherboards still accommodate a Turbo LED. I handle them last because the wiring is not consistent from case to case and motherboard to motherboard, and they have no meaningful function except eliminate the problem of having to explain to a customer why the Turbo LED isn’t on and why the Turbo switch has no real purpose. If I can’t get them to work after a few minutes or fidgeting, I leave them disconnected and bundle them with the other wires with a zip (cable) tie. Sometimes, one must resort to tracing wires to the appropriate LEDs and switches… The last case LED I burned-out in my shop was about five years ago and that was caused by error, not procedure.
Q. What is a SIMM & DIMM? A. A Single In-line Memory Module or SIMM is a small printed circuit board containing memory chips (DRAMs). Most SIMMs have 30 or 72 pins (which are actually printed circuit contacts and not pins). 30-pin SIMMs come in 8-bit (non-parity) or 9-bit (parity). 72-pin SIMMs are generally available in 32-bit (non-parity) or 36-bit (parity) configurations.
A Dual In-line Memory Module or DIMM combines two 72-pin SIMMS into a 168-pin module with 64-bit (non-parity) or 72-bit (parity) data paths.
Q. Will PC133 or PC100 memory work on a motherboard that has a 66 Mhz Front Side Bus (FSB)?
A. Let me answer that with a qualified YES. In general, SDRAM is backward compatible and can run at bus speeds slower than that for which it is rated. For example, the 128 Mbytes of PC133 memory I have in my computer with an EpoX MVP3G2 Super 7 motherboard, which supports PC100 memory, works with a 100 Mhz FSB.. There are a few older 66 Mhz motherboards that will not work PC100 or PC133 memory, but they are exceptions, not the rule.
Frequently Asked Questions about Vista
What is Windows Vista? This is the first question, perhaps, every one asks. Windows Vista, a Microsoft product, is an operating system, which manages the computer’s resources. This is a Graphical User Interface (GUI) based operating system.
When is it gets released and which operating system it precedes? Microsoft has already released it business edition to its business customers in its home state, the US, on 30th November 2006. The official date for releasing other editions has been fixed to January 2007. The operating system will precede Windows XP.
Ok, alright, what are the new features does the operating system carries?
Windows Vista carries a lot of new features. It starts with the desktop view itself. The desktop look has been changed significantly. One can enjoy the 3-D window effects as well as translucent window effects. The other features include more secured Internet Explorer 7.0, Windows Media Player 11, side bar etc.
3-D effect means? Is it the default feature, which is available in all editions of Windows Vista?
The 3D effect to all windows in Windows Vista is termed as Aero. This is not available in Home basic edition of Windows Vista. In other editions, feature will not get installed to your system if the system does not have the DirectX 9.0 supported graphics card with minimum of 128 MB of Graphics Memory.
What are the new features available in Internet Explorer 7.0?
The Internet Explorer 7.0 includes tabbed browsing. One can browse multiple pages in the same window separated by tabs. The browser also got anti-phishing tools to combat phishing. Phishing is a serious crime where by, the user information such as password etc. goes to the hacker’s system.
How many editions are available for Windows Vista? What are they? Windows Vista comes in 5 editions. The editions are Starter, Home basic, Home Premium, business and ultimate. One can select the edition depending on the type of use of computer for his activity.
What is the minimum system requirement to run Windows Vista?
Windows Vista requires a good, a reasonably well configured system to work. However, the requirement will be high as Windows Vista runs a couple of new features. It is said that, the system requirement for running Windows Vista is,
Processor speed – 800 MHz and above.System Memory – 512 M.B.
GPU – SVGA (800×600)
Graphics Memory – 64 MB in case, if running aero.
HDD – 20 GB. (40 GB for well working conditions)
HDD Free Space – 15 GB.
Optical Drive – CD-ROM/DVD ROM.
Audio card – Any, whose drivers support Windows XP.
Internet – Required for activation.
File System – The installation hard drive partition must be NTFS New Technology File System), and this is the crucial point in backing up files.
Clean Install involves removing the existing entire operating system and installing the new one. One need to install every programs etc. again as various settings of the programs including shortcuts gets overwritten. The clean install requires more time than other installation method.
Will the present PC can run Windows Vista? Yes, but, of course, it must meet the minimum system requirements as given above.
Before installation process should I require to take all data backup?
This is a simple question that can be answered by you, yourself. If the data is important to you, then I will advice backup of that data, before installing windows vista. Remember, during installation process any thing may happen. The system may crash or even selecting a wrong partition can take the data beyond recovery. Keep data backup in CD-ROM̢۪s if you can afford to do so.
Should I require converting my existing FAT32 hard disk partition into NTFS while installing Windows Vista? Yes. Microsoft has done an excellent job in protecting the system from Hackers. For security reasons, Microsoft felt the need for conversion from FAT32 into NTFS. Windows Vista will not get installed to a non NTFS partition.
After installation, I was prompted with a window to activate my product. What is it?
After many years of thinking and experimenting, even scratching their heads, Microsoft people found a way to overcome software piracy. Activating the product through the internet, ensure that the product is genuine. The process collects information such as ids of various hardware components installed in the system and sends the information to the activation server. It is kept in the server. If there are more than one installations using same product, then the server rejects the request to activate, and the product installed is termed as non-genuine. If the product is not genuine, then one may not able to get the latest updates, patches, latest major upgrades. If the product is not activated, within 30 days, the product will enter into reduced functionality mode and continues to stay in that mode, till the product is activated.
What are the features available in the various editions of Windows Vista? The features vary depending on the type of editions. The home basic provides only basic features for email and internet access in a more secured environment. Home Basic provides tools such as Windows Defender and Windows Firewall for security. It also includes Internet Explorer 7.0, which is meant for secured browsing.
The home Premium is meant for best computing and entertainment experiences. Home Premium includes features from home basic plus Windows Aero, tools for collaborating and sharing documents. This edition is best suited for laptops. It also provides Windows Media Center, a platform for entertainment. One can enjoy television through Xbox 360.
The third edition is the business edition, which is meant for small and mid-sized organizations. It includes all features of Home Premium, but, excludes media center and Xbox 360 from its list. Instead of these two features, it comes with tools for protecting from hardware failures, provides connectivity to business and remote desktops.
The final and feature rich edition of Windows Vista is the Ultimate. It provides all features of business and home premium and also, provides tool to protect data, in case of computer or hard drive thefts, through bit-locker encryption.
Windows Vista starter edition is a special edition meant for beginners, learners. It includes additional help, tutorials to teach the use of computers among learners. However, this edition will not be made available in the US, United States, Canada, Australia, New Zealand, European Union, or any other high income markets defined by the World Bank.
What is bit locker encryption? Bit locker encryption is tool for encrypting data. Actual data is converted to an unknown form in this technique. It has to be decrypted before use by the user. This keeps data in secured form as actual data is not revealed to the user unless he reveals his correct identity in the form of password or finger print to the system. It is a tool which is very useful for protecting data during the theft of any storage media, such as hard disks.
What is Vista sidebar? What is its use? The side bar is a small window which contains shortcuts to the frequently accessed programs. This window appears on the desktop, there by making it convenient for the users to access programs quickly, without much difficulty.
For example, if one want to access calculator program. The user needs to traverse many paths for accessing the program. For calculator, the user has to click start button, then navigate through Programs menu, and then through Accessories, then finally reach the calculator program. Instead, if the calculator shortcut is placed in the sidebar, one need a single click to access the calculator program! This saves the time and energy in pressing and moving the mouse pointer from here to there.
Windows Vista side bar contains clock which shows time and also gadgets. Gadgets are mini-applications, which offer easy access to information, and also provide easy access to the frequently used tools. For example, a gadget can give one, a glance view of all online instant messaging contacts, the day view from the calendar. It can also give an easy way to control the media player too. One can download more gadgets from the gadget gallery which is available in the Microsoft web site.
What are the features in Windows Defender? Windows Defender is a program which helps the PC to stay protected against spyware and other potentially dangerous, harmful programs. Spyware usually collects the personal information such as password, phone number, credit card numbers etc and sends it to the person, who wants it. Some spyware even can change the configuration settings of the system.
How much time needed to learn Windows Vista? It depends. But, surely it will take some time for an experienced user to get adjusted to the Vista environment. The entire environment has changed, including the desktop. Previously, it was said some users of Windows 3.1 took time to adjust to Windows 95, as the environment, such as screens got changed. People, who saw the working of Windows XP, may feel slightly different in working environment. For example, the start button is no longer labeled as “Start” in Windows Vista.
Will all my softwares that ran comfortably in Windows XP, run in Windows Vista?
This question is slightly difficult to answer at this stage. Testers found comfortable in running these applications without many problems. But, the applications such as Symantec Norton 2007, Winamp, Nero, Disk keeper, Dragon NaturallySpeaking, Adobe Premiere, Pinnacle Studio, and a wide range of games, may cause problems. These programs may not run at all also. Some programs may require you to tweak their some settings to work properly. For such programs, you can go through their official websites for more information on how to tweak settings.
Will the Release of Windows Vista signal the end of road for Windows XP?
No. One can expect Microsoft to give out upgrades, patches for Windows XP too. As of now, the new features such as Internet Explorer 7.0, Windows Media Player 11 have been also extended to Windows XP users. One can expect Microsoft to continue support for Windows XP for another 10 to 15 years. The major upgrade of Windows XP, Service Pack 3 is expected to be released on 2008. It was earlier expected that the Service Pack 3 will be released next year.
Server 2008 Questions And Answers
Q.What are some of the new tools and features provided by Windows Server 2008?
A.Windows Server 2008 now provides a desktop environment similar to Microsoft Windows Vista and includes tools also found in Vista, such as the new backup snap-in and the BitLocker drive encryption feature. Windows Server 2008 also provides the new IIS7 web server and the Windows Deployment Service.
Q.What are the different editions of Windows Server 2008?
A.The entry-level version of Windows Server 2008 is the Standard Edition. The Enterprise Edition provides a platform for large enterprisewide networks. The Datacenter Edition provides support for unlimited Hyper-V virtualization and advanced clustering services. The Web Edition is a scaled-down version of Windows Server 2008 intended for use as a dedicated web server. The Standard, Enterprise, and Datacenter Editions can be purchased with or without the Hyper-V virtualization technology.
Q.What two hardware considerations should be an important part of the planning process for a Windows Server 2008 deployment?
A.Any server on which you will install Windows Server 2008 should have at least the minimum hardware requirement for running the network operating system. Server hardware should also be on the Windows Server 2008 Hardware Compatibility List to avoid the possibility of hardware and network operating system incompatibility.
Q.How does the activation process differ on Windows Server 2008 as compared to Windows Server 2003?
A.You can select to have activation happen automatically when the Windows Server 2008 installation is complete. Make sure that the Automatically Activate Windows When I’m Online check box is selected on the Product Key page.
Q.What are the options for installing Windows Server 2008?
A.You can install Windows Server 2008 on a server not currently configured with NOS, or you can upgrade existing servers running Windows 2000 Server and Windows Server 2003.
Q.How do you configure and manage a Windows Server 2008 core installation?
A.This stripped-down version of Windows Server 2008 is managed from the command line.
Q.Which Control Panel tool enables you to automate the running of server utilities and other applications?
A.The Task Scheduler enables you to schedule the launching of tools such as Windows Backup and Disk Defragmenter.
Q.What are some of the items that can be accessed via the System Properties dialog box?
A.You can access virtual memory settings and the Device Manager via the System Properties dialog box.
Q.Which Windows Server utility provides a common interface for tools and utilities and provides access to server roles, services, and monitoring and drive utilities?
A.The Server Manager provides both the interface and access to a large number of the utilities and tools that you will use as you manage your Windows server.
Q.How are local user accounts and groups created?
A.Local user accounts and groups are managed in the Local Users and Groups node in the Server Manager. Local user accounts and groups are used to provide local access to a server.
Q.When a child domain is created in the domain tree, what type of trust relationship exists between the new child domain and the tree’s root domain?
A.Child domains and the root domain of a tree are assigned transitive trusts. This means that the root domain and child domain trust each other and allow resources in any domain in the tree to be accessed by users in any domain in the tree.
Q.What is the primary function of domain controllers?
A.The primary function of domain controllers is to validate users to the network. However, domain controllers also provide the catalog of Active Directory objects to users on the network.
Q.What are some of the other roles that a server running Windows Server 2008 could fill on the network?
A.A server running Windows Server 2008 can be configured as a domain controller, a file server, a print server, a web server, or an application server. Windows servers can also have roles and features that provide services such as DNS, DHCP, and Routing and Remote Access.
Q.Which Windows Server 2008 tools make it easy to manage and configure a server’s roles and features?
A.The Server Manager window enables you to view the roles and features installed on a server and also to quickly access the tools used to manage these various roles and features. The Server Manager can be used to add and remove roles and features as needed.
Q.What Windows Server 2008 service is used to install client operating systems over the network?
A.Windows Deployment Services (WDS) enables you to install client and server operating systems over the network to any computer with a PXE-enabled network interface.
Q.What domain services are necessary for you to deploy the Windows Deployment Services on your network?
A.Windows Deployment Services requires that a DHCP server and a DNS server be installed in the domain.
Q.How is WDS configured and managed on a server running Windows Server 2008?
A.The Windows Deployment Services snap-in enables you to configure the WDS server and add boot and install images to the server.
Q.What utility is provided by Windows Server 2008 for managing disk drives, partitions, and volumes?
A.The Disk Manager provides all the tools for formatting, creating, and managing drive volumes and partitions.
Q.What is the difference between a basic and dynamic drive in the Windows Server 2008 environment?
A.A basic disk embraces the MS-DOS disk structure; a basic disk can be divided into partitions (simple volumes).
Dynamic disks consist of a single partition that can be divided into any number of volumes. Dynamic disks also support Windows Server 2008 RAID implementations.
Q.What is RAID?
A.RAID, or Redundant Array of Independent Disks, is a strategy for building fault tolerance into your file servers. RAID enables you to combine one or more volumes on separate drives so that they are accessed by a single drive letter. Windows Server 2008 enables you to configure RAID 0 (a striped set), RAID 1 (a mirror set), and RAID 5 (disk striping with parity).
Q.What is the most foolproof strategy for protecting data on the network?
A.Regular backups of network data provides the best method of protecting you from data loss.
Q.What conceptual model helps provide an understanding of how network protocol stacks such as TCP/IP work?
A.The OSI model, consisting of the application, presentation, session, transport, network, data link, and physical layers, helps describe how data is sent and received on the network by protocol stacks.
Q.What protocol stack is installed by default when you install Windows Server 2008 on a network server?
A.TCP/IP (v4 and v6) is the default protocol for Windows Server 2008. It is required for Active Directory implementations and provides for connectivity on heterogeneous networks.
Q.When TCP/IP is configured on a Windows server (or domain client), what information is required?
A.You must provide at least the IP address and the subnet mask to configure a TCP/IP client for an IPv4 client, unless that client obtains this information from a DHCP server. For IPv6 clients, the interface ID is generated automatically from the MAC hardware address on the network adapter. IPv6 can also use DHCP as a method to configure IP clients on the network.
Q.What are two command-line utilities that can be used to check TCP/IP configurations and IP connectivity, respectively?
A.The ipconfig command can be used to check a computer’s IP configuration and also renew the client’s IP address if it is provided by a DHCP server. ping can be used to check the connection between the local computer and any computer on the network, using the destination computer’s IP address.
Q.What term is used to refer to the first domain created in a new Active Directory tree?
A.The first domain created in a tree is referred to as the root domain. Child domains created in the tree share the same namespace as the root domain.
Q.How is a server running Windows Server 2008 configured as a domain controller, such as the domain controller for the root domain or a child domain?
A.Installing the Active Directory on a server running Windows Server 2008 provides you with the option of creating a root domain for a domain tree or of creating child domains in an existing tree. Installing Active Directory on the server makes the server a domain controller.
Q.What are some of the tools used to manage Active Directory objects in a Windows Server 2008 domain?
A.When the Active Directory is installed on a server (making it a domain controller), a set of Active Directory snap-ins is provided. The Active Directory Users and Computers snap-in is used to manage Active Directory objects such as user accounts, computers, and groups. The Active Directory Domains and Trusts snap-in enables you to manage the trusts that are defined between domains. The Active Directory Sites and Services snap-in provides for the management of domain sites and subnets.
Q.How are domain user accounts created and managed?
A.The Active Directory Users and Computers snap-in provides the tools necessary for creating user accounts and managing account properties. Properties for user accounts include settings related to logon hours, the computers to which a user can log on, and the settings related to the user’s password.
Q.What type of Active Directory objects can be contained in a group?
A.A group can contain users, computers, contacts, and other nested groups.
Q.What type of group is not available in a domain that is running at the mixed-mode functional level?
A.Universal groups are not available in a mixed-mode domain. The functional level must be raised to Windows 2003 or Windows 2008 to make these groups available.
Q.What types of Active Directory objects can be contained in an Organizational Unit?
A.Organizational Units can hold users, groups, computers, contacts, and other OUs. The Organizational Unit provides you with a container directly below the domain level that enables you to refine the logical hierarchy of how your users and other resources are arranged in the Active Directory.
Q.What are Active Directory sites?
A.Active Directory sites are physical locations on the network’s physical topology. Each regional domain that you create is assigned to a site. Sites typically represent one or more IP subnets that are connected by IP routers. Because sites are separated from each other by a router, the domain controllers on each site periodically replicate the Active Directory to update the Global Catalog on each site segment.
Q.How can client computer accounts be added to the Active Directory?
A.Client computer accounts can be added through the Active Directory Users and Computers snap-in. You can also create client computer accounts via the client computer by joining it to the domain via the System Properties dialog box. This requires a user account that has administrative privileges, such as members of the Domain Administrator or Enterprise Administrator groups.
Q.What firewall setting is required to manage client computers such as Vista clients and Windows 2008 member servers?
A.The Windows Firewall must allow remote administration for a computer to be managed remotely.
Q.Can servers running Windows Server 2008 provide services to clients when they are not part of a domain?
A.Servers running Windows Server 2008 can be configured to participate in a workgroup. The server can provide some services to the workgroup peers but does not provide the security and management tools provided to domain controllers.
Q.What does the use of Group Policy provide you as a network administrator?
A.Group Policy provides a method of controlling user and computer configuration settings for Active Directory containers such as sites, domains, and OUs. GPOs are linked to a particular container, and then individual policies and administrative templates are enabled to control the environment for the users or computers within that particular container.
Q.What tools are involved in managing and deploying Group Policy?
A.GPOs and their settings, links, and other information such as permissions can be viewed in the Group Policy Management snap-in.
Q.How do you deal with Group Policy inheritance issues?
A.GPOs are inherited down through the Active Directory tree by default. You can block the inheritance of settings from upline GPOs (for a particular container such as an OU or a local computer) by selecting Block Inheritance for that particular object. If you want to enforce a higher-level GPO so that it overrides directly linked GPOs, you can use the Enforce command on the inherited (or upline) GPO.
Q.How can you make sure that network clients have the most recent Windows updates installed and have other important security features such as the Windows Firewall enabled before they can gain full network access?
A.You can configure a Network Policy Server (a service available in the Network Policy and Access Services role). The Network Policy Server can be configured to compare desktop client settings with health validators to determine the level of network access afforded to the client.
Q.What is the purpose of deploying local DNS servers?
A.A domain DNS server provides for the local mapping of fully qualified domain names to IP addresses. Because the DNS is a distributed database, the local DNS servers can provide record information to remote DNS servers to help resolve remote requests related to fully qualified domain names on your network.
Q.What types of zones would you want to create on your DNS server so that both queries to resolve hostnames to IP addresses and queries to resolve IP addresses to hostnames are handled successfully?
A.You would create both a forward lookup zone and a reverse lookup zone on your Windows Server 2008 DNS server.
Q.What tool enables you to manage your Windows Server 2008 DNS server?
A.The DNS snap-in enables you to add or remove zones and to view the records in your DNS zones. You can also use the snap-in to create records such as a DNS resource record.
Q.In terms of DNS, what is a caching-only server?
A.A caching-only DNS server supplies information related to queries based on the data it contains in its DNS cache. Caching-only servers are often used as DNS forwarders. Because they are not configured with any zones, they do not generate network traffic related to zone transfers.
Q.How is the range of IP addresses defined for a Windows Server 2008 DHCP server?
A.The IP addresses supplied by the DHCP server are held in a scope. A scope that contains more than one subnet of IP addresses is called a superscope. IP addresses in a scope that you do not want to lease can be included in an exclusion range.
Q.What TCP/IP configuration parameters can be provided to a DHCP client?
A.The DHCP server can supply a DHCP client an IP address and subnet mask. It also can optionally include the default gateway address, the DNS server address, and the WINS server address to the client.
Q.How can you configure the DHCP server so that it provides certain devices with the same IP address each time the address is renewed?
A.You can create a reservation for the device (or create reservations for a number of devices). To create a reservation, you need to know the MAC hardware address of the device. You can use the ipconfig or nbstat command-line utilities to determine the MAC address for a network device such as a computer or printer.
Q.To negate rogue DHCP servers from running with a domain, what is required for your DHCP server to function?
A.The DHCP server must be authorized in the Active Directory before it can function in the domain.
Networking Interview Questions
0
What is UTP?
UTP — Unshielded twisted pair 10BASE-T is the preferred Ethernet medium of the 90s. It is based on a star topology and provides a number of advantages over coaxial media:
It uses inexpensive, readily available copper phone wire. UTP wire is much easier to install and debug than coax. UTP uses RG-45 connectors, which are cheap and reliable.
What is a router? What is a gateway?
Routers are machines that direct a packet through the maze of networks that stand between its source and destination. Normally a router is used for internal networks while a gateway acts a door for the packet to reach the ‘outside’ of the internal network.
What are LAN and WAN? How do they differ?
LAN stands for Local Area Network. This type of networking system is used to connect the computers over a short range of area the examples would be a network inside office, school, and home and occasionally between buildings etc. WAN stands for Wide Area Network. This type of networking system is used to connect the computer over large range of area; the best example could be the Internet which connects different computer across the world.
What is MAC Address and IP Address?
MAC Address is the physical identifier of a network adapter and IP address represents a logical device address on Internet Protocol Networks. Address Resolution Protocol of IP translates IP addresses to MAC addresses.
What is Network Topology? Which is commonly used?
Network Topology is the style or way in which the networking is done. There are different types of topologies like:
• Ring
• Star
• Extended Star
• Hub
• Spoke
• Mesh
• Bus
What is VPN?
VPN stands for Virtual Private Network. It is a private network that makes use of public network like internet but still it maintains security and privacy of private network through encryption and security procedures.
How many ways u can configure the Router?
The ways to configure the Router are:
• Console
• Telnet
• Auxiliary(AUX)
How to create Proxy server?
Proxy Server can be created using third party software. A proxy server acts as store and forward caches. It receives the requests from different clients for web pages and it finds those pages and forwards it to the client machines.
How to use software that is installed in the server?
One can use Terminal services to connect to the server and run the software. Even clients can use remote desktop connection to access the software.
What is RAID?
RAID stands for Redundant Array of Inexpensive Drives. It is a technology that uses two or more hard disk drives to replicate data among multiple hard disk drives. RAID provides greater levels of performance, reliability and larger data volumes sizes. It is used for mirroring.
What is VoIP and how it works?
VoIP is nothing but Voice over Internet Protocol. It converts voice into digital signal which is transmitted through internet. If we are calling a regular phone then the signal is converted to regular telephone signal before reaching to destination. VoIP allows us to make call directly from a computer.
What is VLAN?
VLAN is nothing but Virtual LAN. It is a network of computers that act as if they are connected to the same network even though they may actually be physically located in different segments of LAN. VLANs are configures through software than hardware. The advantages of VLAN are that even if we move the computer physically it can stay on the same VLAN without requiring any hardware reconfiguration.
What is the difference between L-2 Devices and L-3 Devices?
L-2 Devices works on MAC Address and L-3 Devices works on IP Address. L-2 Devices are much faster when compared to L-3 Devices.
What is default gateway?
Default gateway is basically the entry point from one network and exit from the other network which often routes through the router network.
Explain the disadvantages of circular login?
In circular login method the event of corrupt database, only the last back up data can be restored.
Mention few standard port numbers for SMTP, POP3, LADAP, IMAP4, Global catalog?
SMTP – 25, POP3 – 110, IMAP4 – 143, RPC – 135, LDAP – 389, Global Catalog – 3268
Q: What are the seven layers of the OSI model?
A: The layers are physical, data link, network, transport, session, presentation, and application layers.
Q: In the TCP client-servel model, how does the three-way handshake work in opening connection?
A: The client first sends a packet with sequence “x” to the server. When the server receives this packet, the server will send back another packet with sequence “y”, acknowledging the request of the client. When the client receives the acknowledgement from the server, the client will then send an acknowledge back to the server for acknowledging that sequence “y” has been received.
Q: What is the purpose of exchanging beginning sequence numbers during the the connection in the TCP client-server model?
A: To ensure that any data lost during data transfer can be retransmitted.
Q: How does Asynchronous Transfer Mode (ATM) work?
A: ATM works by transmitting all traffic in small, fixed-sized cells. These small, fixed-size cells reduces queuing delay and can be switched quickly. ATM fits into layer 2 of the OSI model and provides functions for framing and error correction. At the port interface, ATM switches convert cells into frames, and vice versa. ATM provides Quality of Service and traffic shaping.
Q: Given a Class B Network with subnet mask of 255.255.248.0 and a packet addressed to 130.40.32.16, what is the subnet address?
A: Take the 2 addresses, write them in binary form, then AND them. The answer is 130.40.32.0
Q:What is an IP address?
A.Every device connected to the public Internet is assigned a unique number known as an Internet Protocol (IP) address. IP addresses consist of four numbers separated by periods (also called a ‘dotted-quad’) and look something like 127.0.0.1.
In computer networking, an Internet Protocol (IP) address consists of a numerical identification (logical address) that network management assigns to devices participating in a computer network utilizing the Internet Protocol for communication between its nodes.[1] Although computers store IP addresses as binary numbers, they often display them in more human-readable notations, such as 192.168.100.1 (for IPv4), and 2001:db8:0:1234:0:567:1:1 (for IPv6). The role of the IP address has been characterized as follows: “A name indicates what we seek. An address indicates where it is. A route indicates how to get there.”
Q:What is ARP? What is ARP Cache Poisoning?
Address Resolution Protocol (ARP) is a protocol for mapping an Internet Protocol address (IP address) to a physical machine address that is recognized in the local network. For example, in IP Version 4, the most common level of IP in use today, an address is 32 bits long. In an Ethernet local area network, however, addresses for attached devices are 48 bits long. (The physical machine address is also known as a Media Access Control or MAC address.) A table, usually called the ARP cache, is used to maintain a correlation between each MAC address and its corresponding IP address. ARP provides the protocol rules for making this correlation and providing address conversion in both directions.
Q:What is a default gateway? What happens if I don’t have one?
A:A gateway is a routing device that knows how to pass traffic between different subnets and networks. A computer will know some routes (a route is the address of each node a packet must go through on the Internet to reach a specific destination), but not the routes to every address on the Internet. It won’t even know all the routes on the nearest subnets. A gateway will not have this information either, but will at least know the addresses of other gateways it can hand the traffic off to. Your default gateway is on the same subnet as your computer, and is the gateway your computer relies on when it doesn’t know how to route traffic.
The default gateway is typically very similar to your IP address, in that many of the numbers may be the same. However, the default gateway is not your IP address. To see what default gateway you are using, follow the steps below for your operating system.
Q:What is Automatic Private IP Addressing (APIPA)?
A. Windows 98, 98 SE, Me, and 2000 have an Automatic Private IP Addressing (APIPA) feature that will automatically assign an Internet Protocol address to a computer on which it installed. This occurs when the TCP/IP protocol is installed, set to obtain it’s IP address automatically from a Dynamic Host Configuration Protocol server, and when there is no DHCP server present or the DHCP server is not available. The Internet Assigned Numbers Authority (IANA) has reserved private IP addresses in the range of 169.254.0.0 – 169.254.255.255 for Automatic Private IP Addressing.
Q:What is CIDR?
Short for Classless Inter-Domain Routing, an IP addressing scheme that replaces the older system based on classes A, B, and C. With CIDR, a single IP address can be used to designate many unique IP addresses. A CIDR IP address looks like a normal IP address except that it ends with a slash followed by a number, called the IP network prefix. For example: 172.200.0.0/16
The IP network prefix specifies how many addresses are covered by the CIDR address, with lower numbers covering more addresses. An IP network prefix of /12, for example, can be used to address 1,048,576 former Class C addresses. CIDR addresses reduce the size of routing tables and make more IP addresses available within organizations. CIDR is also called supernetting
Q:What does the ping 192.168.0.1 -l 1000 -n 100 command do?
A:The ping command will send roundtrip packets to a destination ( other PC, router, printer, etc.) and see how long it takes. The 192.168.0.1 is the destination ( which, by the way is a typical default IP address of a router. ) The -l 1000 is how big the packet should be in bytes. The default is 32, if the -l parameter is not used. And the -n 100 is saying to send, it 100 times. The default is 4, when this parameter is not used.
Q:Describe the role of the routing table on a host and on a router.
a:In internetworking, the process of moving a packet of data from source to destination. Routing is usually performed by a dedicated device called a router. Routing is a key feature of the Internet because it enables messages to pass from one computer to another and eventually reach the target machine. Each intermediary computer performs routing by passing along the message to the next computer. Part of this process involves analyzing a routing table to determine the best path.
(row´ter) (n.) A device that forwards data packets along networks. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISP’s network. Routers are located at gateways, the places where two or more networks connect. Routers use headers and forwarding tables to determine the best path for forwarding the packets, and they use protocols such as ICMP to communicate with each other and configure the best route between any two hosts.Very little filtering of data is done through routers .
Q:What are routing protocols? Why do we need them? Name a few.
A:Routing protocol is a protocol that specifies how routers communicate with each other to disseminate information that allows them to select routes between any two nodes on a network. Typically, each router has a prior knowledge only of its immediate neighbors. A routing protocol shares this information so that routers have knowledge of the network topology at large.
The term routing protocol may refer more specifically to a protocol operating at Layer 3 of the OSI model which similarly disseminates topology information between routers. Many routing protocols used in the public Internet are defined in documents called RFCs.
There are three major types of routing protocols, some with variants: link-state routing protocols, path vector protocols and distance vector routing protocols.
The specific characteristics of routing protocols include the manner in which they either prevent routing loops from forming or break routing loops if they do form, and the manner in which they determine preferred routes from a sequence of hop costs and other preference factors.
• IGRP (Interior Gateway Routing Protocol)
• EIGRP (Enhanced Interior Gateway Routing Protocol)
• OSPF (Open Shortest Path First)
• RIP (Routing Information Protocol)
• IS-IS (Intermediate System to Intermediate System)
Q .To monitor ipx traffic on a network, what command would you use?
Show ipx traffic
Q. What command would you use to find out the names of Novell servers on a network?
show ipx servers
Q. “arpa” is used by the Cisco IOS for which encapsulation types?
Ethernet_II
Q. To prevent Service Advertisements (SAPs) from flooding a network, Cisco routers do not forward them. How are services advertised to other networks?
Each router builds its own SAP table and forwards that every 60 seconds.
Q. Which type of Ethernet framing is used for TCP/IP and AppleTalk?
Ethernet SNAP
Q Which type of Ethernet framing is used for TCP/IP and DECnet?
Ethernet II
Q. Which NetWare protocol works on layer 3–network layer—of the OSI model?
IPX
Q. Which NetWare protocol provides link-state routing?
NLSP
Q. What is the Cisco name for the encapsulation type used on a serial interface?
HDLC
Q. IGRP uses flash updates, poison reverse updates, holddown times, and split horizon. How often does it broadcast its routing table updates?
90 seconds
Q. When using RIP, routing updates are broadcast every ____ seconds.
30
Q. A default route is analogous to?
Default gateway
Q. What does the command “IP name-server 255.255.255.255″ accomplish?
It sets the domain name lookup to be a local broadcast.
Q. How would you configure one host name that points to two IP addresses?
IP host jacob 1.0.0.5 2.0.0.8
Q. Which IP Address Class can have 64,000 subnets with 64,000 hosts per subnet?
Class B
Q. There are two processes to pair MAC address with IP addresses. Which process finds an IP address from a MAC address?
RARP
Q. Where would network testing be included in an IP packet?
IP Options field
Q. What field tells the Internet layer how to handle an IP packet?
Type of Service
Q. What is the UDP datagram format?
Source Port – 16 bits, Destination Port – 16 bits, Length – 16 Bits, Checksum – 16 bits, Data
Q. What is the function of DDR on Cisco routers?
DDR is dial-on-demand routing. It provides routing for low volume and periodic traffic. It initiates a call to a remote site when there is traffic to transmit.
Q. When using access lists, what does a Cisco router check first?
The first thing checked is to see if the packet is routable or bridgeable. If it is not, the packet will be dropped.
Q. What do the following statements in an extended access list accomplish?
access-list 101 deny TCP 172.16.4.0 0.0.0.255 172.16.3.0 0.0.0.255 eq 21
access-list 101 deny TCP 172.16.4.0 0.0.0.255 172.16.3.0 0.0.0.255 eq 20
access-list 101 permit TCP 172.16.4.0 0.0.0.255 0.0.0.0 255.255.255.255
This will block ftp traffic since ftp uses ports 20 and 21.
Q. Which protocol for PPP LCP (Link Control Protocol) performs a challenge handshake?
CHAP
Q. Which form of PPP error detection on Cisco routers monitors data dropped on a link?
The Quality protocol monitors data dropped on a link. Magic Number avoids frame looping.
Q. Which protocol for PPP provides load balancing across multiple links?
Multilink Protocol (MP)
Q. Which OSI layer end to end communication, segmentation and re-assembly?
Layer 4 the Transport layer performs this function.
Q. What IP command would you use to test the entire IP stack?
Telnet is an application and it resides at the top of the stack it traverses down the stack and up the stack at the receiving end.
Q. What is the default bandwidth of a serial connection?
Default bandwidth is T1.
Q. Which OSI layer handles physical address, network topology?
Layer 2 the Data-Link layer performs this function.
Q Which OSI layer establishes, maintains and terminates sessions between hosts?
Layer 5 the Session layer performs this function.
Q. Where Cisco IOS is stored?
By default the Cisco IOS is stored in flash.
Q. Which layer is responsible for providing mechanisms for multiplexing upper-layer application, session establishment, and tear down of virtual circuits?
The Transport layer does the following: Responsible for end-to-end integrity of data transmission. Handles multiplexing upper-layer application, session establishment and tear down of virtual circuits. Hides details of network dependent info from the higher layers by providing transparent data transfer. The ‘windows’ works at this level to control how much information is transferred before an acknowledgement is required.
Q. What’s the default CDP holdtime in seconds for Cisco routers?
Cisco Discovery Protocol is a proprietary protocol to allow you to access configuration information on other routers and switches with a single command. It uses SNAP at the Data-Link Layer. By default CDP sends out a broadcast every 60 seconds and it holds this information for 180 seconds. CDP is enabled by default.
Q. How can you force the client to give up the dhcp lease if you have access to the client PC?
ipconfig /release
Q:What authentication options do Windows 2000 Servers have for remote clients?
PAP, SPAP, CHAP, MS-CHAP and EAP.
Q.What are the networking protocol options for the Windows clients if for some reason you do not want to use TCP/IP?
NWLink (Novell), NetBEUI, AppleTalk (Apple).
Q.What is data link layer in the OSI reference model responsible for? Data link layer is located above the physical layer, but below the network layer.
Taking raw data bits and packaging them into frames. The network layer will be responsible for addressing the frames, while the physical layer is responsible for retrieving and sending raw data bits.
Q.What is binding order?
The order by which the network protocols are used for client-server communications. The most frequently used protocols should be at the top.
Q.How do cryptography-based keys ensure the validity of data transferred across the network?
Each IP packet is assigned a checksum, so if the checksums do not match on both receiving and transmitting ends, the data was modified or corrupted.
Q.Should we deploy IPSEC-based security or certificate-based security?
They are really two different technologies. IPSec secures the TCP/IP communication and protects the integrity of the packets. Certificate-based security ensures the validity of authenticated clients and servers.
Q.What is LMHOSTS file?
It’s a file stored on a host machine that is used to resolve NetBIOS to specific IP addresses.
Q.What’s the difference between forward lookup and reverse lookup in DNS?
Forward lookup is name-to-address, the reverse lookup is address-to-name.
Q.How can you recover a file encrypted using EFS?
Use the domain recovery agent.
Q.What is a Firewall?
Firewalls are of two types:
-Hardware Firewall
-Software Firewall.
Firewall in simple manner is bascially the utility to provide the security over the network. These are the security measures that prevents the network’s in and out traffic to pass through the specific Security filters so that the unwanted and unsecure data can be stopped from entering into the network..
further… as a security measure it also depends on the network designer and implementer that how to use a Firewall mean to say the security measures like how to present the content filtering and Url filtering which type of firewall should be used and where to put it..
Q.What a protocol actually means?
A Protocol is bascially set of rules designed and developed for the internetwork or can say intranetwork Communications. the need of Tcp had been rised in early years when like.. IBM Mainframe were not able to Communicate with the Burroughs mainframe.. means if you wish to connect 2 or more computers they should be same with everything from manufacturer to designer and implementer…then TCP imerged as a solution-for-ever..
EARLIER it was NCP( Network Control Protocal) but later it refined into TCP( Transmission Control Protocol) and IP(Internet Protocol)on jan.1,1983..
Some General roles of TCP/IP are:
1. Independence from particular vendor or network.
2. very low data overhead
3. good failure recovery.
and if the thinghs are taken seprately.. then
TCP is bascially responsible for proper data transmission by assuring data integrity it is a connection oriented protocol that follows the under scenerio
1. Handshaking.
2. Packect Sequencing
3. Flow Control.
4. Error handling.
IP : Since the data to be sent must be put somewhere the IP works here .. the required data is packaged in an IP packet.
Q.What is the difference between TCP and UDP ?
TCP is a connection oriented protocol, which means that everytime a packet is sent say from host A to B, we will get an acknowledgement. Whereas UDP on the other hand, is a connection less protocol.
Where will it be used : TCP -> Say you have a file transfer and you need to ensure that the file reaches intact, and time is not a factor, in such a case we can use TCP.
UDP-> Media Streaming, question is say you are watching a movie…would you prefer that your movie comes..perfectly….but u need to wait a long time before you see the next frame ?..or would you prefer the movie to keep streaming…Yes…The second option is definely better….This is when we need UDP
MS Exchange Interview Questions
1. What must be done to an AD forest before Exchange can be deployed?
Setup.exe /forestprep
2. What Exchange process is responsible for communication with AD?
DSACCESS
3. What 3 types of domain controller does Exchange access?
Normal Domain Controller, Global Catalog, Configuration Domain Controller
4. What connector type would you use to connect to the Internet, and what are the two methods of sending mail over
that connector?
SMTP Connector: Forward to smart host or use DNS to route to each address
5. How would you optimise Exchange 2003 memory usage on a Windows Server 2003 server with more than 1Gb of memory?
Add /3Gb switch to boot.ini
6. Name the process names for the following:
System Attendant? MAD.EXE, Information Store – STORE.EXE, SMTP/POP/IMAP/OWA – INETINFO.EXE
7. What is the maximum amount of databases that can be hosted on Exchange 2003 Enterprise?
20 databases. 4 SGs x 5 DBs.
8. What are the standard port numbers for SMTP, POP3, IMAP4, RPC, LDAP and Global Catalog?
- 25 SMTP
- 110 POP3
- 143 IMAP4
- 135 RPC
- 389 LDAP
- 636 LDAP (SSL)
- 3268 Global Catalog
- 465 SMTP/SSL,
- 993 IMAP4/SSL
- 563 IMAP4/SSL
- 53 DNS ,
- 80 HTTP
- 88 Kerberos
- 110 POP3
- 119 NNTP
9. What are the prequisite for installation of Exchange Server ?
The pre requsite are
IIS, SMTP, WWW service ,NNTP, W3SVC NET Framework
ASP.NET
Then run Forestprep
The run domainprep.
10. Which protocol is used for Public Folder ?
ANS: NNTP
11. What is the use of NNTP with exchange ?
ANS: This protocol is used the news group in exchange
12. Disaster Recovery Plan?
Ans: Deals with the restoration of computer system with all attendent software and connections to full functionality under a variety of damaging or interfering external condtions.
13. About the new features in Exchange 2003:
1.Updated Outlook Web Access.
2.Updated VSAPI (Virus Scanning Application Programming Interface)
but in Exchange Server 2003 Enterprise, there are Specific Features which :
3.Eight-node Clustering using the Windows Clustering service in Windows Server
(Ent.&Datacenter)
4.Multiple storage groups.
5..X.400 connectors which supports both TCP/IP and X.25.
14. What would a rise in remote queue length generally indicate?
This means mail is not being sent to other servers. This can be explained by outages or performance issues with the network or
remote servers.
15. What would a rise in the Local Delivery queue generally mean?
This indicates a performance issue or outage on the local server. Reasons could be slowness in consulting AD, slowness in handing messages off to local delivery or SMTP delivery. It could also be databases being dismounted or a lack of disk space.
16. What are the disadvantages of circular logging?
In the event of a corrupt database, data can only be restored to the last backup.
17. What is the maximum storage capacity for Exchange standard version? What would you do if it reaches maximum capacity?”
Ans: 16GB.Once the store dismounts at the 16GB limit the only way to mount it again is to use the 17GB registry setting. And even this is a temporary solution. if you apply Exchange 2003 SP2 to your Standard Edition server, the database size limit is initially increased to 18GB. Whilst you can go on to change this figure to a value up to 75GB, it’s important to note that 18GB is the default setting HKLM\System\CurrentControlSet\Services\MSExchangeIS\{server name}\Private-{GUID It therefore follows that for registry settings that relate to making changes on a public store, you’ll need to work in t he following registry key:
HKLM\System\CurrentControlSet\Services\MSExchangeIS\{server name}\Public-{GUID}
Under the relevant database, create the following registry information: Value type: REG_DWORD
Value name: Database Size Limit in GB
Set the value data to be the maximum size in gigabytes that the database is allowed to grow to. For the Standard Edition of Exchange, you can enter numbers between 1 and 75. For the Enterprise Edition, you can enter numbers between 1 and 8000. Yes, that’s right, between 1GB and 8000GB or 8TB. Therefore, even if you are running the Enterprise Edition of Exchange, you can still enforce overall database size limits of, say, 150GB if you so desire..
18. What is MIME & MAPI?
MIME = Multipurpose Internet Mail Extensions It defines non-ASCII message formats. It is a coding standard that defines the structure of E-Mails and other Internet messages. MIME is also used for declaration of content from other Internet protocols like HTTP, Desktop environments like KDE, Gnome or Mac OS X Aqua. The standard is defined in RFC 2045.
With MIME it is possible to exchange information about the type of messages (the content type) between the sender and the recipient of the message. MIME also defines the art of coding (Content-Transfer-Encoding). These are different coding methods defined for the transportation of non ASCII characters in plain text documents and non text documents like Images, Voice and Video for transportation through text based delivery systems like e-mail or the Usenet.
The non text elements will be encoded from the sender of the message and will be decoded by the message recipient. Coding of non ASCII characters is often based on “quoted printable” coding, binary data typically using Base64-coding.
There is an extension of this Standard called S/MIME (Secure Multipurpose Internet Mail Extensions) that allows the signing and encryption of messages. There are other e-mail encryption solutions like PGP/MIME (RFC 2015 and 3156).
MAPI = Messaging Application Programming Interface It’s the programming interface for email. It is a Microsoft Windows program interface that enables you to send e-mail from within a Windows application and attach the document you are working on to the e-mail note. Applications that take advantage of MAPI include word processors, spreadsheets, and graphics applications. MAPI-compatible applications typically include a Send Mail or Send in the File pulldown menu of the application. Selecting one of these sends a request to a MAPI server.
19.List the services of Exchange Server 2003?
There are several services involved with Exchange Server, and stopping different services will accomplish different things. The services are interdependent, so when you stop or start various services you may see a message about having to stop dependent services. If you do stop dependent services, don’t forget to restart them again when you restart the service that you began with.
To shut down Exchange completely on a given machine, you need to stop all of the following services:
Microsoft Exchange Event (MSExchangeES) :-This service was used for launching event-based scripts in Exchange 5.5 when folder changes were detected. Exchange 2000 offered the ability to create Event Sinks directly, so this use of this service has decreased. This service is not started by default.
Microsoft Exchange IMAP4 (IMAP4Svc):-This service supplies IMAP4 protocol message server functionality. This service is disabled by default. To use IMAP4 you must enable this service, configure it to auto-start, and start the service.
Microsoft Exchange Information Store (MSExchangeIS) :-This service is used to access the Exchange mail and public folder stores. If this service is not running, users will not be able to use Exchange. This service is started by default.
Microsoft Exchange Management (MSExchangeMGMT):-This service is responsible for various management functions available through WMI, such as message tracking. This service is started by default.
Microsoft Exchange MTA Stacks (MSExchangeMTA):-This service is used to transfer X.400 messages sent to and from foreign systems, including Exchange 5.5 Servers. This service was extremely important in Exchange 5.5, which used X.400 as the default message transfer protocol. Before stopping or disabling this service, review MS KB 810489. This service is started by default.
Microsoft Exchange POP3 (POP3Svc):-This service supplies POP3 protocol message server functionality. This service is disabled by default. To use POP3 you must enable this service, configure it to auto-start, and start the service.
Microsoft Exchange Routing Engine (RESvc):-This service is used for routing and topology information for routing SMTP based messages. This service is started by default.
Microsoft Exchange System Attendant (MSExchangeSA):-This service handles various cleanup and monitoring functions. One of the most important functions of the System Attendant is the Recipient Update Service (RUS), which is responsible for mapping attributes in Active Directory to the Exchange subsystem and enforcing recipient policies. When you create a mailbox for a user, you simply set some attributes on a user object. The RUS takes that information and does all of the work in the background with Exchange to really make the mailbox. If you mailbox-enable or mail-enable objects and they don’t seem to work, the RUS is
one of the first places you will look for an issue. If you need to enable diagnostics for the RUS, the parameters are maintained in a separate service registry entry called MSExchangeAL. This isn’t a real service; it is simply the supplied location to modify RUS functionality. This service is started by default.
Microsoft Exchange Site Replication Service (MSExchangeSRS):-This service is used in Organizations that have Exchange 5.5 combined with Exchange 2000/2003. This service is not started by default.
Network News Transfer Protocol (NntpSvc) :-This service is responsible for supplying NNTP Protocol Server functionality. This service is started by default.
Simple Mail Transfer Protocol (SMTPSVC):-This service is responsible for supplying SMTP Protocol Server functionality. This service is started by default.
20.How can you recover a deleted mail box ?
In Exchange, if you delete a mailbox, it is disconnected for a default period of 30 days (the mailbox retention period), and you can reconnect it at any point during that time. Deleting a mailbox does not mean that it is permanently deleted (or purged) from the information store database right away, only that it is flagged for deletion. At the end of the mailbox retention period, the mailbox is permanently deleted from the database. You can also permanently delete the mailbox by choosing to purge it at any time.
This also means that if you mistakenly delete a mail-enabled user account, you can recreate that user object, and then reconnect that mailbox during the mailbox retention period.
Configure the deleted mailbox retention period at the mailbox store object level.
To Delete a Mailbox in Exchange
1. Right-click the user in Active Directory Users and Computers.
2. Click Exchange Tasks.
3. Click Next on the Welcome page of the Exchange Task Wizard.
4. Click Delete Mailbox.
5. Click Next, click Next, and then click Finish.
The mailbox is now flagged for deletion and will be permanently deleted at the end of the mailbox retention period unless you recover it.
To Reconnect (or Recover) a Deleted Mailbox
1. In Exchange System Manager, locate the mailbox store that contains the disconnected mailbox.
2. Click the Mailboxes object under the mailbox store.
3. If the mailbox is not already marked as disconnected (the mailbox icon appears with a red X), right-click the Mailboxes object, and then click Cleanup Agent.
4. Right-click the disconnected mailbox, click Reconnect, and then select the appropriate user from the dialog box that appears.
5. Click OK.
Note Only one user may be connected to a mailbox because all globally unique identifiers (GUIDs) are required to be unique across an entire forest
.To Reconnect a Deleted Mailbox to a New User Object
1. In Active Directory Users and Computers, create a new user object. When you create the new user object, click to clear the Create an Exchange Mailbox check box.
You will connect this user account to an already existing mailbox.
2. Follow steps 1 through 4 in the preceding “To Reconnect (or Recover) a Deleted Mailbox” section.
To Configure the Mailbox Retention Period
1. Right-click the mailbox store, and then click Properties.
2. On the Limits tab, change the Keep deleted mailboxes for (days) default setting of 30 to the number of days you want.
3. Click OK.
21.what is the use of ESUtil.exe ?
Repair the database. ESEUTIL is a tool to defragment your exchange databases offline, to check their integrity and to repair a damaged/lost database.
ESEUTIL is located in the \EXCHSRVR\BIN directory. This directory is not in the system path so you must open the tool in the BIN directory or enhance the system path with the \EXCHSRVR\BIN directory.
You can use the Eseutil utility to defragment the information store and directory in Microsoft Exchange Server 5.5 and to defragment the information store in Microsoft Exchange 2000 Server and in Microsoft Exchange Server 2003. Eseutil examines the structure of the database tables and records (which can include reading, scanning, repairing, and defragmenting) the low level of the database (Ese.dll). Eseutil is located in the Winnt\System32 folder in Exchange Server 5.5 and in the Exchsrvr/Bin folder in Exchange 2000 and in Exchange 2003. The utility can run on one database at a time from the command line.
22. If you have deleted the user, after you recreated the same user. How you will give the access of previous mail box ?
Reconnect the Deleted user’ s mailbox to the recreated user. Provided the recreated user doesn’t have mailbox .
23. Which protocol is used for Public Folder ?
NNTP Network News Transfer Protocol, both nntp and imap helps clients to access the public folder. but actually, Smtp send the mails across the public folder.
24. What is latest service pack Exchange 2003?
SP2
25. What is latest service pack Exchange 2000?
SP4
26. What is the name of Exchange Databases?
priv1.edb
27 How many databases in Standard Exchange version.?
1
28 How many databases in Enterprise Exchange version ?
20
29: What is the definition of site, administrative group, and routing group in a mixed organization?
Ans: An Exchange site is a server grouping for both administrative and topological purposes. In a mixed organization, the servers running Exchange 5.5 recognize sites, while the servers running Exchange 2000 recognize both administrative and routing groups. The Active Directory Connector automatically replicates each Exchange 5.5 site to Exchange 2000 as both an administrative group with a routing group of the same name.
30: How does an Exchange 5.5 site relate to an Exchange 2000 administrative group?
Ans: In a mixed or native Exchange 2000/Exchange 5.5 topology, these are mapped 1:1. The administrative group is mainly for permissions mapping, although the administrative group is used to create the legacy-distinguished name (DN).
31: How do messages get from an Exchange 2000 server to an Exchange 5.5 server in the same site/routing group?
Ans: An Exchange 2000 server evaluates whether the server is in the same routing group or not. If it is, then the server sends the message through the Message Transfer Agent (MTA), which creates a direct local area network (LAN), MTA, RPC connection. If it is not, the server routes the message to the routing group of the destination server through connectors.
32: How do messages get from an Exchange 2000 server to another Exchange 2000 server in a mixed routing group?
Ans: Exchange 2000 servers, whether in a mixed or pure routing group, always use SMTP to send messages from one server to another. The SMTP Service will open a direct connection to the destination server. However, Exchange 2000 servers will route based on routing groups, not administrative groups.
33: How does a Windows 2000 domain relate to an Exchange 2000 organization?
Ans: There is no relationship. All configuration information for Exchange 2000 is stored in the Active Directory configuration naming context. This is replicated to every domain controller to each domain in the forest. Therefore, Exchange Organization information is available for read/write in every domain.
34: How does a Windows 2000 site relate to an Exchange 2000 routing group?
Ans: An Exchange routing group is a collection of Exchange 2000 servers with high-availability to one another, but not necessarily high bandwidth. Although the concept of the Windows 2000 site and the Exchange routing group are quite similar, there are no alignment prerequisites for deployment. Routing groups are defined in the configuration naming context of the Active Directory.
35: How does a Windows 2000 domain relate to an Exchange 2000 routing group?
Ans; There is no relationship. An Active Directory domain contains users and computer information for those that reside in that domain. An Exchange routing group contains information about Exchange 2000 servers that have high-availability to one another.
36: How does a Windows 2000 forest relate to an Exchange organization?
Ans: In Exchange 2000, there is a limitation of exactly one Exchange organization per Windows 2000 Active Directory forest. Conversely, every server within a given Exchange organization must be in the same Active Directory forest.
37: What is the purpose of a routing group?
Ans; The routing group is the smallest unit of servers likely to be connected to one another at all times. The routing group is one node on the graph of connector paths with multiple possible connectors between routing groups.
Within a routing group, or before routing has been configured by the creation of a routing group, mail from one server to another goes point-to-point using SMTP.
If you wish to have direct point-to-point routing between a collection of Exchange 2000 servers, you can place them into the same routing group. In general, you design your routing group boundaries based upon connectivity and availability of the network. Between routing groups, you can define connectors that route messages between these routing group collections. It is common practice to use a routing group connector (RGC) to accomplish this.
38: What does it mean for a connector to go down?
Ans: If the source bridgehead cannot contact the destination bridgehead, then the system, by default, retries for 10 minutes. After 10 minutes, the bridgehead is marked unavailable. If there are other target bridgeheads on the connector, those are tried instead. Once all target bridgeheads on the connector are tagged as unavailable, then the whole connector is marked down and other routes are evaluated. If there are other available routes, message(s) are rerouted. If there are no other routes available, the message will sit in the local queue until the connector comes back up.
39: What does the routing service do when a local connector is down?
Ans: When the SMTP Service or X.400 Service notices that a connector is down, it notifies the routing service of this. The routing service marks the connection as down in its routing state graph.
40: What exactly does a routing master do?
Ans: The routing master coordinates changes to link state that are learned by servers within its routing group. When one single server coordinates changes, it is possible to treat a routing group as a single entity and to compute a least-cost path between routing groups. All servers in the routing group advertise and act upon the same information.
41: What happens when it goes down?
Ans: All servers in the routing group continue to operate on the same information that they had at the time they lost contact with the master. This cannot cause mail to loop, because all servers continue to operate on loop-free information.
When the master comes back up, it starts with all servers and connectors marked up. As it learns about down servers, it reconstructs the link state information and passes it around.
42: How do SMTP and X.400 servers communicate link state information within a routing group?
Ans: Each server communicates with the master through a TCP-based Link State Algorithm (LSA) protocol developed in the transport core development team. Each server, including the master, is on TCP listening port 691 and registered with Internet Assigned Numbers Authority (IANA) for this purpose. The master broadcasts changes only to all servers in its routing group.
43: What are the file names for the essential exchange database?
Ans: Priv1.EDB, Priv1.STM
44: What are the core exchange serives? Are they the same on exchange 5.5 and 2000?
Ans: Information Store Service, System Attendant Service, Routing Engine
45: What ports do LDAP and GC use?
Ans: LDAP=389 GC=3268
46: What is DNS port & protocol
Ans: 53
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51: How do you administer the new remote wipe feature in SP2?
A. The new remote wipe capability requires the Microsoft Exchange ActiveSync Mobile Web Administration tool, one of a collection of Web tools that will be available in late 2005. The Exchange ActiveSync Mobile Administration Web tool was created as a separate Web tool so that Help desk staff or non–Exchange Server administrators can be delegated the right to manage devices.
47: How do you administer the new remote wipe feature in SP2?
A. The new remote wipe capability requires the Microsoft Exchange ActiveSync Mobile Web Administration tool, one of a collection of Web tools that will be available in late 2005. The Exchange ActiveSync Mobile Administration Web tool was created as a separate Web tool so that Help desk staff or non–Exchange Server administrators can be delegated the right to manage devices.
48: What is Outlook Web Access?
A. Outlook Web Access is a service of Exchange Server that enables users to access their Exchange Server mailboxes through a Web browser. By using Outlook Web Access, a server that is running Exchange Server can also function as a Web site that enables authorized users to read or send e-mail messages, manage their calendar, or perform other e-mail functions over the Internet. Outlook Web Access can be deployed in an Exchange Server front-end/back-end server deployment.
49: What are front-end and back-end Exchange servers?
A. Exchange Server can be deployed in a front-end and back-end server configuration where the front-end component that serves to authenticate and proxy HTTP requests is deployed on an Exchange front-end server separate from an Exchange back-end server holding the Exchange Server Outlook Web Access functionality and information store, meaning the users’ mailboxes and public folders, among other things.
50: What are Kerberos and NTLM?
A. Kerberos and NTLM are two different authentication protocols. Kerberos is the preferred Windows authentication protocol used whenever possible and is the default protocol used by Exchange Server 2003 between front-end and back-end Exchange servers for Outlook Web Access. If for some reason Kerberos authentication would fail or is disabled, Outlook Web Access would fall back to using NTLM between the front-end and back-end Exchange servers. Note that Kerberos is called “Negotiate” when used over HTTP.
51: What is the difference between a primary and a non-primary connection agreement?
A. A primary connection agreement replicates existing directory objects. It also creates and replicates new directory objects in the destination directory. A non-primary connection agreement only replicates information in pre-existing objects.
A connection agreement type has two check boxes selected by default, even if a connection agreement already exists. These are “This is a primary connection agreement for the connected Exchange organization” and “This is a primary connection agreement for the connected Windows domain.”
If you are using more than one connection agreement to replicate Microsoft Windows 2000 user accounts for a single Exchange Server 5.5 organization, there should be only one primary connection agreement. Using multiple primary connection agreements to replicate the same Exchange 5.5 organization will result in creating duplicate objects.
52: Q. What is the name-matching rule, and how do I set it?
A. You can customize directory object–matching rules on the From Exchange tab and the From Windows tab. The name-matching rule should be set to its default setting. You should change this only when the Active Directory directory service and the Exchange 5.5 directory have several common objects, for example, when inter-forest replication is in place. Matching rules should be changed so that object attributes in each of the directories have different values, for example, a Simple Mail Transfer Protocol (SMTP) address or a security identifier (SID).
53: Is there any way to compress data with Exchange 2000 before sending it to another server?
A. At this time, SMTP servers do not have compression for mail. The specification for mail servers, however, includes a standard for implementing compression. The TLS extension helps maintain message security through both compression and encryption. Encryption is usually more secure if the data is not plain text, and to make compression unpredictable, you should compress before encryption. Exchange Server supports the TLS extension.
Our transport events technology also makes it very easy for Microsoft or a third-party software vendor to release an extension to Exchange 2000 that would automatically compress and decompress messages as they come into or go out of Exchange. In most cases, compression overhead taxes the CPU of the Exchange server. This reduces performance, often offsetting any network bandwidth you gained through compression. Thus, it’s probably better to build more functionality into the client, where you may have idle CPU cycles to spare, than to tax the server with compression.
Note: Current TLS implementations do not use any compression algorithms.
54: Can Exchange 2000 run on top of a different Microsoft Windows SMTP Server from Microsoft Internet Information Server (IIS) 5.0?
A. No, Exchange 2000 requires and works in concert with the server events extensibility that are built into the SMTP server. This ships as part of IIS 5.0 in Windows 2000.
55: How is the host name of an internal or external server resolved?
A. The SMTP Service takes a name, call it “REMOTE,” which might be a server’s internal fully qualified domain name (FQDN) or an external FQDN of an e-mail domain. For example, user@domain.com looks up “domain.com” and resolves it. The following steps should be taken to accomplish this:
• Check the domain name system (DNS) for the mail exchanger (MX) record for REMOTE.
• If DNS returns >0 entries, connect to port 25 on each one, in lowest priority order first.
• If DNS returns “Authoritative Host Not Found [1],” non-delivery report (NDR) the message immediately. This is returned if the name server accesses the root (.) node of DNS and does not find a record for the domain name.
• If DNS returns any other error, or returns no MX entries, then fall through to step 2 and call gethostbyname() for REMOTE. This results in both an A record search as well as WINS lookup.
Note: By default, Windows 2000 DNS ships with the IP addresses of the InterNIC root name servers pre-populated in its configuration. This means that a request for a domain that is not defined in a zone on the DNS server will be forwarded to one of those servers. If your server is behind a firewall and cannot reach these servers, you will not get “Authoritative Host Not Found,” but rather “Server Failed.”
56: How does a Windows 2000 site relate to an Exchange 2000 organization?
A. There is no relationship. A Windows 2000 site is defined as a group of resources (computers, servers, etc.) that have high-connectivity to one another. An Exchange organization encompasses the entire forest and bears no relationship to the topological site structure that the Active Directory administrator defines.
57: How does the connector get designated as up again?
A. The SMTP Service creates a special connection that has zero messages, but tries the remote side of the connector according to the retry interval for the virtual server. When the connection succeeds, the service updates routing with the new information that the connector is back up.
58: Q. Does having a single routing master introduce a single point of failure?
A. No. Exchange 2000 may send mail to a server whose link is down, but mail will continue to flow, since Exchange will automatically switch to sub-optimal routing if a routing master fails. Exchange 2000 enables the administrator to manually change the routing master role from one server to another.
59: How do servers (both SMTP and X.400) communicate link state information between routing groups?
A. When two servers communicate through SMTP, Exchange 2000 uses a version of LSA protocol that works as an extension to SMTP through the SMTP Service Extensions (ESMTP) framework. Exchange 2000 servers advertise X-LINK2STATE support during the EHLO. When one Exchange 2000 server sees another advertising that, it attempts to trade routing information. Routing information will only be traded if the two servers are in the same organization (a DIGEST string is compared). This only occurs in the event of per-routing-group differences in transferred information.
Between routing groups, when servers communicate through X.400, Exchange 2000 uses a version of LSA. The MTA constructs a “dummy” X.400 message to transfer this information.
60: How often do servers that connect between routing groups communicate link state updates? Are messages used?
A. In the case of link state updates tunneled through SMTP, messages are not used. Instead, when there is an update, a connection is created to the neighboring routing group. During the course of that connection, the link state information is transferred. In fact, even if there is no new information on the source side, during each SMTP transmission between two Exchange 2000 servers in the same organization, they will exchange link state information.
In the case of link state updates through X.400 between two Exchange 2000 servers, a “dummy message” is created that includes the link state update information.
61: Why have all of this routing?
A. Network routers use the Open Shortest Path First (OSPF) protocol to route packets optimally between servers. The single-source, shortest-path algorithm, used by the Exchange routing service, is very similar to the OSPF internal routing protocol used by many enterprise networks, except that Exchange provides more information than simply IP source and destination. Exchange can route messages according to destination, message size sender, and message priority.
Note: The similarity between OSPF, and the routing algorithm used by Exchange 2000, is that they are both derived from Dijkstra’s algorithm. Using the same type of algorithms is where this similarity ends. You do not have to deploy OSPF before deploying Exchange 2000.
Another reason to route messages through logical connectors is to optimize message bandwidth. If a single message is destined for recipients on five different servers in a remote location, point-to-point communication causes the message body to be sent five times. By funneling that through a messaging bridgehead, the message body is only sent once, which makes a significant difference with large messages.
Note: Certain connectors may be limited as to what size messages they will take. This is not referring to the IP address of the sender, but rather the actual e-mail address of the sender. Certain connectors may be limited by who may use them.
62: Does Exchange ActiveSync require SSL authentication?
A. It depends on the device. Windows Mobile 2002 powered devices connect over Secure Sockets Layer (SSL). Windows Mobile 2003 powered devices do not require SSL. However, it is strongly recommended that you use SSL to protect your data and credentials. To enable SSL authentication on Windows Mobile 2003 powered devices, in the ActiveSync Server Synchronization settings, select the This server uses an SSL connection option.
63: How can I control which users have access to Exchange ActiveSync?
A. By default, all users are enabled for Exchange ActiveSync. An Exchange Server administrator can globally disable Exchange ActiveSync for all users in Exchange System Manager by using the Mobile Settings option under Global Settings. You can also enable or disable individual users by using Active Directory Users and Computers.
64: What types of data can be synchronized by using Exchange ActiveSync?
A. Exchange ActiveSync enables you to synchronize your e-mail messages, calendar, and contacts lists in your Exchange Server 2003 mailbox with a Microsoft Windows Mobile powered device.
65: What are the core services in Exchange 5.5? Exlplain the order of starting the services?
Ans: 1. Directory service(DS): “net start msexchangeds”
2. Information Store(IS): “net start msexchangeis”
3. Message Transfer Agent(MTA): “net start msexchangemta”
4. Internet Mail Connector(IMC): “net start msexchangeimc”
5. “net start msexchangees”
66.what is Distribution List?
Ans: Distribution list is a term sometimes used for a function of email clients where lists of email addresses are used to email everyone on the list at once. This can be referred to as an electronic mailshot. It differs from a mailing list, electronic mailing list or the email option found in an Internet forum as it is usually for one way traffic and not for coordinating a discussion. In effect, only members of a distribution list can send mails to the list.
67.We are running an Exchange 2003 server using Panda Antivirus. Panda needs to have access to the public folders for monitoring and scanning purposes. Both Exchange and Panda were installed by using the Administrator account and password. However, Panda is now telling us that Panda and Administrator have no rights to the public folders. This keeps Exchange from allowing e-mail into the mail server.
Ans:-Here is what has likely happened to you: Recently the password for Administrator was changed. The Panda software uses a service account to run the Panda services. During the install, you probably specified the Administrator account as the service account. Now the service will not work until you update the password on the Panda service
To update the password, open the services.msc snap-in, locate the Panda service(s) and view the properties of the service by clicking on the Log On tab. Change the password and click OK
68.We are using an Exchange 2000 server and Outlook 2003. We have some public folders (Contacts, etc). When we were using Outlook XP, it worked fine. But now, we can’t see public folders with Outlook 2003. What can we do to use and synchronize it again? In Outlook 2003, public folders are not at the bottom of the tree where they used to be. Click on the folder button at the bottom of the navigation pane. The folder list will appear, and then click Public Folders. You may want to add public folder to your favorite folder list.
Ans:-Unpredictable things can happen if a Microsoft Exchange public folder’s objects are moved out of the Exchange System Objects organizational unit (OU). For one, you may get the following error when you try to view the properties of a mail-enabled folder affected by such a change:
The format of the specified domain name is invalid
Facility: Win32
ID no: c00704bc
Exchange System Manager
You’d think that the solution would be to just move the affected objects back into the right OU using Exchange System Manager — but it isn’t that easy. One of the odder bits of asymmetry in Exchange System Manager is that an object can be moved out of the Exchange System Objects OU, but cannot be moved into it. That’s right — not even if it originally belonged there in the first place. (From what I have been able to tell, this is to prevent the OU from getting “contaminated” by things that aren’t supposed to be there, which makes sense, but doesn’t help us fix the problem!)
The only way to move objects into the Microsoft Exchange System Objects OU is through the ADSI Edit tool, which is included with Windows 2000/2003 on the \Support\Tools folder on the installation CD.
To restore the public folders to their original OU:
1. Run the ADSI Edit tool.
2. Open the Domain NC container, inside which you’ll see a tree structure similar to the Active Directory Users and Computers hierarchy.
3. Open the OU that the public folder directory objects were moved into.
4. Locate the directory object in that OU and right-click on it.
5. Select Move, and then the Microsoft Exchange System Objects OU.
Server Support Questions L2-L3 PART-2
Posted by Anuj Sharma on July 31st, 2010 | 1 Comment
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Features of windows2003
Automated System Recovery (ASR) provides a facility to get Windows Server 2003 systems back up and running quickly after a failure occurs.
Internet Information Service 6.0 (By default will not install) Highly secured and locked down by default, new architectural model that includes features such as process isolation and a met abase stored in XML format.
Saved Queries: Active Directory Users and Computers now includes a new node named Saved Queries, which allows an administrator to create a number of predefined queries that are saved for future access.
Group Policy Management Console (GPMC) is a new a new tool for managing Group Policy in Windows Server 2003. While Group Policy–related elements have typically been found across a range of tools—such as Active Directory Users And Computers, the Group Policy MMC snap-in, and others—GPMC acts as a single consolidated environment for carrying out Group Policy–related tasks.
RSoP tool, the administrator could generate a query that would process all the applicable Group Policy settings for that user for the local computer or another computer on the network. After processing the query, RSoP would present the exact Group Policy settings that apply to that user, as well as the source Group Policy object that was responsible for the setting.
Remote Desktop: In Windows Server 2003, Terminal Services Remote Administration mode is known as Remote Desktop. Remote Desktop connections are enabled via the Remote tab in the System applet in Control Panel. When connecting to a terminal server using an RDP 5.1 client, many of the local resources are available within the remote session, including the client file system, smart cards, audio (output), serial ports, printers (including network), and the clipboard.
Cross-Forest Trust Relationships : Windows Server 2003 supports cross-forest transitive trust relationships to allow users in one forest to access resources in any domain in another, and vice versa.
Domain Renaming & Domain Controller renaming is possible.
Universal Group Membership Caching: Windows Server 2003 introduces a new feature aimed at reducing the need for global catalog servers at all remote locations. Universal group membership caching is a new feature that can be enabled on selected domain controllers, making them capable of caching universal group information locally without being a full-fledged global catalog server.
Volume shadow copies of shared folders feature makes point-in-time backups of user data to ensure that previous versions are easily accessible in cases where a user has accidentally deleted a file.
Application Directory Partitions: Active Directory forest has a copy of the schema partition, which defines the object types that can be created, and their associated properties. Similarly, all domain controllers in the forest hold a copy of the configuration partition, which holds information about sites and services. Within a domain, all domain controllers hold a copy of the domain partition, which includes information about the objects
within that particular domain only.
Application directory partition. This new partition is unique in that it allows directory information to be replicated to certain domain controllers only, on an as-necessary basis. Specifically designed for directory- enabled applications and services, application directory partitions can contain any type of object, with the exception of security principals such as users, computers, or security group accounts.
Distributed File System: DFS is enhanced for Windows Server 2003, Enterprise Edition and Windows Server, Datacenter Edition by allowing multiple DFS roots on a single server. You can use this feature to host multiple DFS roots on a single server, reducing administrative and hardware costs of managing multiple namespaces and multiple replicated namespaces.
Improvements in Clustering:
In Datacenter Edition, the maximum supported cluster size has been increased from 4-nodes in Windows 2000, to 8-nodes in Windows Server 2003.
In Enterprise Edition, the maximum supported cluster size has been increased from 2-nodes in Windows 2000 Advanced Server to 8-nodes in Windows Server 2003.
Server clusters running Windows Server 2003, Enterprise Edition or Datacenter Edition integrate with the Microsoft Active Directory® service.
This integration ensures that a “virtual” computer object is registered in Active Directory. This allows applications to use Kerberos authentication and delegation to highly available services running in a cluster. The computer object also provides a default location for Active Directory-aware services to publish service control points.
Server clusters are fully supported on computers running the 64-bit versions of Windows Server 2003. Windows Server 2003 supports Encrypting File System (EFS) on clustered (shared) disks.
RIS server supports to deploy all editions of Windows 2000, Windows XP Professional, and all editions of Windows Server 2003 (except Windows 2000 Datacenter Server and Windows Server 2003, Datacenter Edition.) In addition, administrators can use RIS servers using Risetup to deploy Windows XP 64-bit Edition and the 64- bit versions of Windows Server 2003.
Point-to-PointProtocoloverEthernet(PPPoE) : Windows Server 2003 delivers a native PPPoE driver for making broadband connections to certain Internet service providers (ISPs) without the need for additional software.
Small businesses or corporate branch offices may also utilize PPPoE’s demand dial capabilities to integrate with the Routing and Remote Access service and NAT.
Internet Connection Firewall (ICF): ICF, designed for use in a small business, provides basic protection on computers directly connected to the Internet or on local area network (LAN) segments. ICF is available for LAN, dial-up, VPN, or PPPoE connections. ICF integrates with ICS or with the Routing and Remote Access service.
Open File Backup: The backup utility included with Windows Server 2003 now supports “open file backup”. In Windows 2000, files had to be closed before initiating backup operations. Backup now uses shadow copies to ensure that any open files being accessed by users are also backed up.(Need to modify some registry keys)
Stub Zones: This is introduced in windows 2003 DNS. A stub zone is like a secondary zone in that it obtains its resource records from other name servers (one or more master name servers). A stub zone is also read-only like a secondary zone, so administrators can’t manually add, remove, or modify resource records on it. First, while secondary zones contain copies of all the resource records in the corresponding zone on the master name server, stub zones contain only three kinds of resource records:
a. A copy of the SOA record for the zone.
b. Copies of NS records for all name servers authoritative for the zone.
c. Copies of (glue)A records for all name servers authoritative for the zone.
That’s it–no CNAME records, MX records, SRV records, or A records for other hosts in the zone. So while a secondary zone can be quite large for a big company’s network, a stub zone is always very small, just a few records. This means replicating zone information from master to stub zone adds almost nil DNS traffic to your network as the records for name servers rarely change unless you decommission an old name server or deploy a new one.
Difference between NT & 2000
Windows NT SAM database is a flat database. And windows 2000 active directory database is a hierarchical database.
In Windows NT only PDC is having writable copy of SAM database but the BDC is only having read only database. In case of Windows 2000 both DC and ADC is having write copy of the database.
Windows NT will not support FAT32 file system. Windows 2000 supports FAT32.
Default authentication protocol in NT is NTLM (NT LAN manager). In windows 2000 default authentication protocol is Kerberos V5.
Features introduced in windows 2000, those are not in Windows NT.
NTFS v5 supports Disk quotas.
Remote Installation Service
Built in VPN & NAT support
IPv6 supports.
USB support.
Distributed File System.
Clustering support.
ICS (Internet Connection Sharing)
Difference between PDC & BDC
PDC contains a write copy of SAM database where as BDC contains read only copy of SAM database. It is not possible to reset a password with out PDC in Windows NT. But both can participate in the user authentication. If PDC fails, we have to manually promote BDC to PDC from server manger.
Difference between DC & ADC.
There is no difference between in DC and ADC both contains write copy of AD. Both can also handles FSMO roles (If transfers from DC to ADC). Functionality wise there is no difference. ADC just require for load balancing & redundancy. If two physical sites are segregated with WAN link come under same domain, better to keep one ADC in other site, and act as a main domain controller for that site. This will reduce the WAN traffic and also user authentication performance will increase.
What is DNS & WINS
DNS is a Domain Naming System/Server, use for resolve the Host names to IP addresses and also do the IP address to host name. It uses fully qualified domain names. DNS is a Internet standard used to resolve host names. Support up to 256 characters.
WINS is a Windows Internet Name Service, which resolves Netbios names to IP Address and also resolve the IP address to Netbios names. This is proprietary of Microsoft and meant for windows only. Support up to 15 characters.
If DHCP server is not available what happens to the client
First time client is trying to get IP address DHCP server, If DHCP server is not found. C IP address from APIPA (Automatic Private I P Address) range 169.254.0.0 -169.254.255.255
If client already got the IP and having lease duration it use the IP till the lease duration expires.
What are the different types of trust relationships
Implicit Trusts —– Establish trust relationship automatically.
Explicit Trusts —– We have to build manually trust relationship .NT to Win2k or
Forest to Forest
Transitive —– If A B C then A C
Non-Transitive —– If A B C then A is not trusting C One way —– One side
Two way —– two sides
Windows Server 2003 Active Directory supports the following types of trust relationships:
Tree-root trust Tree-root trust relationships are automatically established when you add a new tree root domain to an existing forest. This trust relationship is transitive and two-way.
Parent-child trust Parent-child trust relationships are automatically established when you add a new child domain to an existing tree. This trust relationship is also transitive and two-way.
Shortcut trust Shortcut trusts are trust relationships that are manually created by systems administrators. These trusts can be defined between any two domains in a forest, generally for the purpose of improving user logon and resource access performance. Shortcut trusts can be especially useful in situations where users in one domain often need to access resources in another, but a long path of transitive trusts separates the two domains. Often referred to as cross-link trusts, shortcut trust relationships are transitive and can be configured as one-way or two-way as needs dictate.
Realm trust Realm trusts are manually created by systems administrators between a non–Windows
Kerberos realm and a Windows Server 2003 Active Directory domain. This type of trust relationship provides cross-platform interoperability with security services in any Kerberos version 5 realm, such as a UNIX implementation. Realm trusts can be either transitive or non-transitive, and one-way or two-way as needs dictate.
External trust External trusts are manually created by systems administrators between Active Directory domains that are in different forests, or between a Windows Server 2003 Active Directory domain and a Windows NT 4.0 domain. These trust relationships provide backward compatibility with Windows NT 4.0 environments, and communication with domains located in other forests that are not con-figured to use forest trusts. External trusts are nontransitive and can be configured as either one-way or two-way as needs dictate.
Forest trust Forest trusts are trust relationships that are manually created by systems administrators between forest root domains in two separate forests. If a forest trust relationship is two-way, it effectively allows authentication requests from users in one forest to reach another, and for users in either forest to access resources in both. Forest trust relationships are transitive between two forests only and can be configured as either one-way or two-way as needs dictate.
By default implicit two way transitive trust relationships establish between all domains in the windows
2000/2003 forest.
What is the process of DHCP for getting the IP address to the client?
Discover —– Client broadcast the packets to find the DHCP server
Offer —– Server offers
Request for IP address —- Client request for IP address to the offered server.
Acknowledge —– Server sends the Acknowledgement to the client
NACK ——– If client not get the IP address after server given offer, then Server sends the Negative
Acknowledgement.
DHCP Server uses port no.: 67
DHCP Client uses port no.: 68
Brief explanation of RAID Levels
A volume is a storage unit made from free space on one or more disks. It can be formatted with a file system and assigned a drive letter. Volumes on dynamic disks can have any of the following layouts: simple, spanned, mirrored, striped, or RAID-5.
A simple volume uses free space from a single disk. It can be a single region on a disk or consist of multiple, concatenated regions. A simple volume can be extended within the same disk or onto additional disks. If a simple volume is extended across multiple disks, it becomes a spanned volume.
A spanned volume is created from free disk space that is linked together from multiple disks. You can extend a spanned volume onto a maximum of 32 disks. A spanned volume cannot be mirrored and is not fault-tolerant.
A striped volume is a volume whose data is interleaved across two or more physical disks. The data on this type of volume is allocated alternately and evenly to each of the physical disks. A striped volume cannot be mirrored or extended and is not fault-tolerant. Striping is also known as RAID-0.
A mirrored volume is a fault-tolerant volume whose data is duplicated on two physical disks. All of the data on one volume is copied to another disk to provide data redundancy. If one of the disks fails, the data can still be accessed from the remaining disk. A mirrored volume cannot be extended. Mirroring is also known as RAID-1.
A RAID-5 volume is a fault-tolerant volume whose data is striped across an array of three or more disks. Parity (a calculated value that can be used to reconstruct data after a failure) is also striped across the disk array. If a physical disk fails, the portion of the RAID-5 volume that was on that failed disk can be re-created from the remaining data and the parity. A RAID-
The system volume contains the hardware-specific files that are needed to load Windows (for example, Ntldr, Boot.ini, and Ntdetect.com). The system volume can be, but does not have to be, the same as the boot volume.
The boot volume contains the Windows operating system files that are located in the
%Systemroot% and %Systemroot%\System32 folders. The boot volume can be, but does not have to be, the same as the system volume.
RAID 0 – Striping
RAID 1- Mirroring (minimum 2 HDD required)
RAID 5 – Striping With Parity (Minimum 3 HDD required)
RAID levels 1 and 5 only gives redundancy
What is the process of user authentication (Kerberos V5) in windows 2000
After giving logon credentials an encryption key will be generated which is used to encrypt the time stamp of the client machine. User name and encrypted timestamp information will be provided to domain controller for authentication. Then Domain controller based on the password information stored in AD for that user it decrypts the encrypted time stamp information. If produces time stamp matches to its time stamp. It will provide logon session key a
Server Support Questions L2-L3
Posted by Anuj Sharma on July 27th, 2010 | 6 Comments
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New Features of windows2003 ACTIVE DIRECTORY
• Easier Deployment and Management
• ADMT version 2.0—migrates password from NT4 to 2000 to 20003 or from 2000 to 2003
• Domain Rename— supports changing Domain Name System and/or NetBios name
• Schema Redefine— Allows deactivation of attributes and class definitions in the Active directory schema
• AD/AM— Active directory in application mode is a new capability of AD that addresses certain deployment scenarios related to directory enabled applications
• Group Policy Improvements—-introduced GPMC tool to manage group policy
• UI—Enhanced User Interface
• Grater Security
• Cross-forest Authentication
• Cross-forest Authorization
• Cross-certification Enhancements IAS and Cross-forest authentication Credential Manager
• Software Restriction Policies
• Improved Performance and Dependability
• Easier logon for remote offices
• Group Membership replication enhancements
• Application Directory Partitions
• Install Replica from media
• Dependability Improvements— updated Inter-Site Topology Generator (ISTG) that scales better by supporting forests with a greater number of sites than Windows 2000.
FILE AND PRINT SERVICES
1. Volume shadow copy service
2. NTFS journaling file system
3. EFS
4. Improved CHDSK Performance
5. Enhanced DFS and FRS Shadow copy of shared folders Enhanced folder redirection
6. Remote document sharing (WEBDAV)
IIS
Fault-tolerant process architecture—– The IIS 6.0 fault-tolerant process architecture isolates Web sites and applications into self-contained units called application pools
Health Monitoring—- IIS 6.0 periodically checks the status of an application pool with automatic restart on failure of the Web sites and applications within that application pool, increasing application availability. IIS 6.0 protects the server, and other applications, by automatically disabling Web sites and applications that fail too often within a short amount of time
Automatic Process Recycling— IIS 6.0 automatically stops and restarts faulty Web sites and applications based on a flexible set of criteria, including CPU utilization and memory consumption, while queuing requests
Rapid-fail Protection—- If an application fails too often within a short amount of time, IIS 6.0 will automatically disable it and return a “503 Service Unavailable” error message to any new or queued requests to the application.
Edit-While-Running
2. Difference between NT & 2000
• NT SAM database is a flat database. Where as in windows 2000 active directory database is a hierarchical database.
• In windows NT only PDC is having writable copy of SAM database but the BDC is only read only database. In case of Windows 2000 both DC and ADC is having write copy of the database
• Windows NT will not support FAT32 file system. Windows 2000 supports FAT32
• Default authentication protocol in NT is NTLM (NT LAN manager). In windows 2000 default authentication protocol is Kerberos V5.
• Windows 2000 depends and Integrated with DNS. NT user Netbios names
• Active Directory can be backed up easily with System state data.
3. Difference between 2000 & 2003
• Application Server mode is introduced in windows 2003.
• Possible to configure stub zones in windows 2003 DNS
• Volume shadow copy services is introduced.
• Windows 2003 gives an option to replicate DNS data b/w all DNS servers in forest or All DNS servers in the domain.
Refer Question 1 for all Enhancements
4. Difference between PDC & BDC
PDC contains a write copy of SAM database where as BDC contains read only copy of SAM database. It is not possible to reset a password or create objects with out PDC in Windows NT.
5. Difference between DC & ADC
There is no difference between in DC and ADC both contains write copy of AD. Both can also handles FSMO roles (If transfers from DC to ADC). It is just for identification. Functionality wise there is no difference.
6. What is DNS & WINS
DNS is a Domain Naming System, which resolves Host names to IP addresses. It uses fully qualified domain names. DNS is a Internet standard used to resolve host names
WINS is a Windows Internet Name Service, which resolves Netbios names to IP Address. This is proprietary for Windows.
7. what is the process of DHCP for getting the IP address to the client
There is a four way negotiation process b/w client and server
DHCP Discover (Initiated by client)
DHCP Offer (Initiated by server)
DHCP Request (Initiated by Client)
DHCP Acknowledgement (Initiated by Server)
In Short From We Can Say DORA
8. What are the port numbers for FTP, Telnet, HTTP, DNS
FTP-21, Telnet – 23, HTTP-80, DNS-53, Kerberos-88, LDAP-389
9. what is the database files used for Active Directory ?
The key AD database files—edb.log, ntds.dit, res1.log, res2.log, and edb.chk—all of which reside in \%systemroot%\ntds on a domain controller (DC) by default. During AD installation, Dcpromo lets you specify alternative locations for these log files and database file NTDS.DIT.
10What is the location of AD Database ?
%System root%/NTDS/NTDS>DIT
11. What is the authentication protocol used in NT
NTLM (NT LAN Manager)
12. What is subnetting and supernetting ?
Subnetting is the process of borrowing bits from the host portion of an address to provide bits for identifying additional sub-networks.
Supernetting merges several smaller blocks of IP addresses (networks) that are continuous into one larger block of addresses. Borrowing network bits to combine several smaller networks into one larger network does supernetting.
13. what is the use of terminal services
Terminal services can be used as Remote Administration mode to administer remotely as well asApplication Server Mode to run the application in one server and users can login to that server to user that application.
14. what is the protocol used for terminal services
RDP
15 what is the port number for RDP
3389
16.what is the difference between Authorized DHCP and Non Authorized DHCP
To avoid problems in the network causing by mis-configured DHCP servers, server in windows 2000 must be validate by AD before starting service to clients. If an authorized DHCP finds any DHCP server in the network it stop serving the clients
17. Difference between inter-site and intra-site replication. Protocols using for replication.
Intra-site replication can be done between the domain controllers in the same site. Inter-site replication can be done between two different sites over WAN links BHS (Bridge Head Servers) is responsible for initiating replication between the sites. Inter-site replication can be done B/w BHS in one site and BHS in another site. We can use RPC over IP or SMTP as a replication protocols where as Domain partition is not possible to replicate using SMTP
18. How to monitor replication
We can user Replmon tool from support tools
19. What are the different backup strategies are available
• Normal Backup
• Incremental Backup
• Differential Backup
• Daily Backup
• Copy Backup
20.What is a global catalog ?
Global catalog is a role, which maintains Indexes about objects. It contains full information of the objects in its own domain and partial information of the objects in other domains. Universal Group membership information will be stored in global catalog servers and replicate to all GC’s in the forest.
21. What is Active Directory and what is the use of it
Active directory is a directory service, which maintains the relation ship between resources and enabling them to work together. Because of AD hierarchal structure windows 2000 is more scalable, reliable. Active directory is derived from X.500 standards where information is stored is hierarchal tree like structure. Active directory depends on two Internet standards one is DNS and other is LDAP. Information in Active directory can be queried by using LDAP protocol
22 what is the physical and logical structure of AD
Active directory physical structure is a hierarchal structure which fallows Forests—Trees—Domains— Child Domains—Grand Child—etc Active directory is logically divided into 3 partitions
• 1.Configuration partition
• 2. Schema Partition
• 3. Domain partition
• 4. Application Partition (only in windows 2003 not available in windows 2000)
Out of these Configuration, Schema partitions can be replicated between the domain controllers in the in the entire forest. Where as Domain partition can be replicated between the domain controllers in the same domain.
23 What is the process of user authentication (Kerberos V5) in windows 2000
After giving logon credentials an encryption key will be generated which is used to encrypt the time stamp of the client machine. User name and encrypted timestamp information will be provided to domain controller for authentication. Then Domain controller based on the password information stored in AD for that user it decrypts the encrypted time stamp information. If produces time stamp matches to its time stamp. It will provide logon session key and Ticket granting ticket to client in an encryption format. Again client decrypts and if produced time stamp information is matching then it will use logon session key to logon to the domain. Ticket granting ticket will be used to generate service granting ticket when accessing network resources
24. what are the port numbers for Kerberos, LDAP and Global catalog
Kerberos – 88, LDAP – 389, Global Catalog – 3268
25 what is the use of LDAP (X.500 standard?)
LDAP is a directory access protocol, which is used to exchange directory information from server to clients or from server to servers
26. what are the problems that are generally come across DHCP ?
Scope is full with IP addresses no IP’s available for new machines If scope options are not configured properly eg default gateway Incorrect creation of scopes etc
27.what is the role responsible for time synchronization
PDC Emulator is responsible for time synchronization. Time synchronization is important becauseKerberos authentication depends on time stamp information
28. what is TTL & how to set TTL time in DNS
TTL is Time to Live setting used for the amount of time that the record should remain in cache when name resolution happened. We can set TTL in SOA (start of authority record) of DNS.
29.What is recovery console
Recovery console is a utility used to recover the system when it is not booting properly or not at all booting. We can perform fallowing operations from recovery console We can copy, rename, or replace operating system files and folders Enable or disable service or device startup the next time that start computer Repair the file system boot sector or the Master Boot Record Create and format partitions on drives
30.What is RIS and what are its requirements ?
RIS is a remote installation service, which is used to install operation system remotely.
Client requirements
• PXE DHCP-based boot ROM version 1.00 or later NIC, or a network adapter that is supported by the RIS boot disk.
• Should meet minimum operating system requirements
Software Requirements
• Below network services must be active on RIS server or any server in the network
• Domain Name System (DNS Service)
• Dynamic Host Configuration Protocol (DHCP)
• Active directory “Directory” service
31.What is FSMO Roles ?
Flexible single master operation (FSMO) roll are
• Domain Naming Master
• Schema Master
• PDC Emulator
• Infrastructure Master
• RID Master
Brief all the FSMO Roles
Domain Naming master and schema master are forest level roles. PDC emulator, Infrastructure master and RID master are Domain level roles; First server in the forest performs all 5 roles by default. Later we can transfer the roles.
Domain Naming Master: Domain naming master is responsible for maintaining the relation ship between the domains. With out this role it is not possible to add or remove any domain.
Schema Master: Schema contains set of classes and attributes. eg User, computer, printer are the objects in AD which are having their own set of attributes.. Schema master is responsible for maintaining this schema. Changes to the schema will affect entire forest.
PDC Emulator: Server, which is performing this role, acts as a PDC in a mixed mode to synchronize directory information between windows 2000 DC to Windows NT BDC. Server, which is performing thisrole, will contain latest password information. This role is also responsible for time synchronization in the forest.
Infrastructure Master: It is responsible for managing group membership information in the domain. This role is responsible for updating DN when name or location of the object is modified.
RID Master: Server, which is performing this role, will provide pool of RID to other domain controllers in the domain. SID is the combination of SID and RID SID=SID+RID where SID is Security identifier common for all objects in the domain and RID is relative identifier unique for each object
32.How to manually configure FSMO Roles to separate DC’s
We can configure manually by two ways :-
Through MMC
We can configure Domain Naming Master role through Active directory domains and trusts We can configure Schema Master role through Active Directory schema Other Three roles we can configure by Active directory users and computers .
Through command promt
By using command NTDSUTIL—type ROLES—type CONNECTIONS—CONNECT TO SERVER SERVERNAME where server name is the name of the domain controller that you want to assign role--– Type transfer role, where role is the role that you want to transfer. For a list of roles that you can transfer, type ? at the fsmo maintenance prompt, and then press ENTER, or see the list of roles at the start of this article. For example, to transfer the RID master role, type transfer rid master. The one exception is for the PDC emulator role, whose syntax is transfer pdc, not transfer pdc emulator.
33. What is the difference between authoritative and non-authoritative restore
In authoritative restore, Objects that are restored will be replicated to all domain controllers in the domain. This can be used specifically when the entire OU is disturbed in all domain controllers or specifically restore a single object, which is disturbed in all DC’s In non-authoritative restore, Restored directory information will be updated by other domain controllers based on the latest modification time.
34.what is Active Directory De-fragmentation
De-fragmentation of AD means separating used space and empty space created by deleted objects and reduces directory size (only in offline De-fragmentation)
35.Difference between online and offline de-fragmentation ?
Online De-fragmentation will be performed by garbage collection process, which runs for every 12 hours by default which separate used space and white space (white space is the space created because of object deletion in AD eg User) and improves the efficiency of AD when the domain controller up and running
Offline defragmentation can be done manually by taking domain controller into Restoration mode. We can only reduce the file size of directory database where as the efficiency will be same as in online defragmentation.
36.What is tombstone period ?
Tombstones are nothing but objects marked for deletion. After deleting an object in AD the objects will not be deleted permanently. It will be remain 60 days by default (which can be configurable) it adds an entry as marked for deletion on the object and replicates to all DC’s. After 60 days object will be deleted permanently from all Dc’s.
37.How to deploy the patches and what are the software’s used for this process
Using SUS (Software update services) server we can deploy patches to all clients in the network. We need to configure an option called “Synchronize with Microsoft software update server” option and schedule time to synchronize in server. We need to approve new update based on the requirement. Then approved update will be deployed to clients We can configure clients by changing the registry manually or through Group policy by adding WUAU administrative template in group policy.
38.hat is Clustering. Briefly define & explain it ?
Clustering is a technology, which is used to provide High Availability for mission critical applications. We can configure cluster by installing MCS (Microsoft cluster service) component from Add remove programs, which can only available in Enterprise Edition and Data center edition.
In Windows we can configure two types of clusters
NLB (network load balancing) cluster for balancing load between servers. This cluster will not provide any high availability. Usually preferable at edge servers like web or proxy.
Server Cluster: This provides High availability by configuring active-active or active-passive cluster. In 2 node active-passive cluster one node will be active and one node will be stand by. When active server fails the application will FAILOVER to stand by server automatically. When the original server backs we need to FAILBACK the application
Quorum: A shared storage need to provide for all servers which keeps information about clustered application and session state and is useful in FAILOVER situation. This is very important if Quorum disk fails entire cluster will fails.
Heartbeat: Heartbeat is a private connectivity between the servers in the cluster, which is used to identify the status of other servers in cluster.
39.How to configure SNMP
SNMP can be configured by installing SNMP from Monitoring and Management tools from Add and Remove programs. For SNMP programs to communicate we need to configure common community name for those machines where SNMP programs (eg DELL OPEN MANAGER) running. This can be configured from services.msc— SNMP service — Security.
40.Is it possible to rename the Domain name & how?
In Windows 2000 it is not possible. In windows 2003 it is possible. On Domain controller by going to MYCOMPUTER properties we can change
. What is SOA Record
SOA is a Start of Authority record, which is a first record in DNS, which controls the startup behavior of DNS. We can configure TTL, refresh, and retry intervals in this record.
41.Is it possible to rename the Domain name & how?
In Windows 2000 it is not possible. In windows 2003 it is possible. On Domain controller by going to MYCOMPUTER properties we can change.
42. What is SOA Record
SOA is a Start of Authority record, which is a first record in DNS, which controls the startup behavior of DNS. We can configure TTL, refresh, and retry intervals in this record.
43.What is a Stub zone and what is the use of it.
Stub zones are a new feature of DNS in Windows Server 2003 that can be used to streamline name resolution, especially in a split namespace scenario. They also help reduce the amount of DNS traffic on your network, making DNS more efficient especially over slow WAN links.
44.What is ASR (Automated System Recovery) and how to implement it
ASR is a two-part system; it includes ASR backup and ASR restore. The ASR Wizard, located in Backup, does the backup portion. The wizard backs up the system state, system services, and all the disks that are associated with the operating system components. ASR also creates a file that contains information about the backup, the disk configurations (including basic and dynamic volumes), and how to perform a restore.
You can access the restore portion by pressing F2 when prompted in the text-mode portion of setup. ASR reads the disk configurations from the file that it creates. It restores all the disk signatures, volumes, and partitions on (at a minimum) the disks that you need to start the computer. ASR will try to restore all the disk configurations, but under some circumstances it might not be able to. ASR then installs a simple installation of Windows and automatically starts a restoration using the backup created by the ASR Wizard.
45.What are the different levels that we can apply Group Policy ?
We can apply group policy at SITE level—Domain Level—OU level
46.What is Domain Policy, Domain controller policy, Local policy and Group policy
Domain Policy will apply to all computers in the domain, because by default it will be associated with domain GPO, Where as Domain controller policy will be applied only on domain controller. By default domain controller security policy will be associated with domain controller GPO. Local policy will be applied to that particular machine only and effects to that computer only
47.What is the use of SYSVOL folder
Policies and scripts saved in SYSVOL folder will be replicated to all domain controllers in the domain. FRS (File replication service) is responsible for replicating all policies and scripts .
48.What is folder redirection?
Folder Redirection is a User group policy. Once you create the group policy and link it to the appropriate folder object, an administrator can designate which folders to redirect and where To do this, the administrator needs to navigate to the following location in the Group Policy Object:
User Configuration\Windows Settings\Folder Redirection
In the Properties of the folder, you can choose Basic or Advanced folder redirection, and you can designate the server file system path to which the folder should be redirected.
The %USERNAME% variable may be used as part of the redirection path, thus allowing the system to dynamically create a newly redirected folder for each user to whom the policy object applies
Nice blog... Deep packet analysis will assist your network monitor to identify the contents of packets passing around the network.
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