IT Certification & Interview Help.

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System Administrator Interview Questions Part 1

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Q : What are SOA records?
Ans : 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.

Q : Brief about Disk Management?
Ans : Windows2000 includes a powerful tool to manage disk-it’s called a disk management. Disk management tool is graphical tool. you can use disk management to:
• Create and format partitions
• Upgrade a disk from basic to dynamic
• Revert form a dynamic to basic
• Create and format Simple, Spanned, Striped, Mirrored and Raid-5 volumes and as well as deleted the same.
• Recover from single hard disk failure in Mirrored and Raid-5 volumes.

Simple Volumes
A simple volume is volume that consists of formatted disk space on a sigle hard disk. You can create simple volumes only on dynamic disks. There is no fault tolerance. If it is fails all data in the simple volume is lost unless the data backed up.

Spanned volumes
A spanned volume consists of formatted disk space on more than one hard disk. That is treated as single volume. The primary purpose and use of spanned volumes is to access disk space on more than one hard disk by using a single drive letter. A spanned volume is some times used when a volume becomes full and u wants to enlarge its capacity. Spanned volumes do not perform any fault tolerance function.

Stripped volumes – Raid level 0
A stripped volume consists of identical-sized areas of formatted disk space located on two or more dynamic disks. In a stripped volume data stored,
A block at time, evenly and sequentially, among all of the disks in the stripped volume. Stripped volumes do not perform any fault tolerance function. Stripped volumes provide faster disk access, because the stripped volume store a single file across multiple disks

Mirrored Volumes – Raid level 1
A mirrored volume consists of a simple volume that is exactly duplicated, in its entirety on to a second dynamic disk. A mirrored volume is accessed by using single drive letter. A mirrored volume provides a highest fault tolerance available in win2000.

Raid-5 Volumes
A Raid-5 Volumes consists of identical sized areas of formatted disk space located on three or more dynamic disks. In Raid-5 volume data is stored a block at a time, evenly and sequentially among all of the disks in the volume. Raid-5 volumes to provide fault tolerance. If Raid-5 volume fails the information on the other disk in the volume is used to regenerate the data from the failed disk. If more than one disk in Raid-5 volumes fails, you cannot recover your unless the data is backed up.


Q: Difference b/w NT and 2000?

A: 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 contained 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.

Q : What is the process of user authentication (Kerberos V5) in windows 2000.

A : 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.

Q : WINS AND DNS.
A. DNS is a Domain Naming System, which resolves Host names to IP addresses. It uses fully qualified domain names. DNS is an 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.

Q : What is DNS? What are the zones? What are the role? What are the records?

A: DNS standard for Domain Name System. The primary purpose of DNS, which consists of a set of specified naming rules and implementations standards, is to provide host name resolutions.
Zones:
A Zone is storage database for either a dns domain or for a dns domain and one are more of it’s subdomains. This storage database is often implemented as a text file called a zone file.
Zone are not created by default when the DNS server services is installed – they are created and configured by administrator.
Forward lookup zone:
This type zone contain host name to ip address mappings and information about available services for either a DNS domain or DNS domain and one or more sub domains.
Reverse lookup zones:
This type of zones contains IP address to host name mappings.
Standard Primary Zone: This type of zone can be either a forward lookup and reverse lookup zones. In either case, the standard primary zone is master copy of that zone. All other copies of the standard primary zone are standard secondary zones.
Active Directory-integrated zone: This type of zone can be either a forward lookup or reverse lookup zone. In either case the active directory – integrated zone is the master copy of that zone.
Standard Secondary Zone: This type of zone is a copy of either a Standard primary zone or an Active directory-integrated zone. Standard secondary zones must be created on different DNS servers than the DNS server that contains the master copy of the zone. The purpose of standard secondary zones is to provide load balancing and fault tolerance for the zone.

Roles
Standard primary
Standard secondary
Active Directory integrated
Master
Caching
Forwarder
Root Server
SRV Records
Msdcs
Sites
Tcp
Udp

Q : what is the process of DHCP for getting the IP address to the client
A: 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 Acknowledgement (Initiated by Server)
DHCP Negative Acknowledgement (Initiated by server if any issues after DHCP offer)

Q: What are the different backup strategies are available ?
A: Normal Backup
Incremental Backup
Differential Backup
Daily Backup
Copy Backup

A) In Differential backup, after taking the backup it will not clear the archive bit, whereas in incremental backup after taking the backup it clears the archive bit.Diffarential backup will take time during the backup, whereas it will take less time during the restore. Incremental backup will take less time during the backup, whereas it will take more time during the restore.

Scenario: I took Full backup on Sunday,incremaental backups from Monday to wednesday. Thursday my server went down.What do i need to do? You need to restore Sunday full backup first and then Monday incremental, like that sequentially till Wednesday.

Q: 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.


Q: 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

Q: 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
Q: what is DFS & its usage
DFS is a distributed file system used to provide common environment for users to access files and folders even when they are shared in different servers physically.
There are two types of DFS domain DFS and Stand alone DFS. We cannot provide redundancy for stand alone DFS in case of failure. Domain DFS is used in a domain environment which can be accessed by /domain name/root1 (root 1 is DFS root name). Stand alone DFS can be used in workgroup environment which can be accessed through /server name/root1 (root 1 is DFS root name). Both the cases we need to create DFS root ( Which appears like a shared folder for end users) and DFS links ( A logical link which is pointing to the server where the folder is physically shared)
The maximum number of Dfs roots per server is 1.
The maximum numbers of Dfs root replicas are 31.
The maximum number of Dfs roots per domain is unlimited.
The maximum number of Dfs links or shared folders in a Dfs root is 1,000

Q: 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





Q: 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 this role, 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

Q: 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.

Q: 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

Q: 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.

Q: 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

Q: 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.

Q: How to deploy the patches and what are the softwares 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

Q: What 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

Q: What are the different types of partitions present in AD

Active directory is divided into three partitions
Configuration Partition—replicates entire forest
Schema Partition—replicates entire forest
Domain Partition—replicate only in domain
Application Partition (Only in Windows 2003)
An application directory partition is a directory partition that is replicated only to specific domain controllers. A domain controller that participates in the replication of a particular application directory partition hosts a replica of that partition. Only domain controllers running Windows Server 2003 can host a replica of an application directory partition.
Applications and services can use application directory partitions to store application-specific data. Application directory partitions can contain any type of object, except security principals. TAPI is an example of a service that stores its application-specific data in an application directory partition.
Application directory partitions are usually created by the applications that will use them to store and replicate data. For testing and troubleshooting purposes, members of the Enterprise Admins group can manually create or manage application directory partitions using the Ntdsutil command-line tool.
Q: What are the (two) services required for replication
File Replication Service (FRS)
Knowledge Consistency Checker (KCC)

Q: Can we use a Linux DNS Sever in 2000 Domain
We can use, But the BIND version should be 8 or greater

Q: 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.

What are the different levels that we can apply Group Policy
We can apply group policy at SITE level---Domain Level---OU level

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.
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
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.

What different modes in windows 2003 (Mixed, native & intrim….etc)
Different Active Directory features are available at different functional levels. Raising domain and forest functional levels is required to enable certain new features as domain controllers are upgraded from Windows NT 4.0 and Windows 2000 to Windows Server 2003
Domain Functional Levels: Windows 2000 Mixed mode, Windows 2000 Native mode, Windows server 2003 and Windows server 2003 interim ( Only available when upgrades directly from Windows NT 4.0 to Windows 2003)
Forest Functional Levels: Windows 2000 and Windows 2003

Ipsec usage and difference window 2000 & 2003.

Microsoft doesn’t recommend Internet Protocol security (IPSec) network address translation (NAT) traversal (NAT-T) for Windows deployments that include VPN servers and that are located behind network address translators. When a server is behind a network address translator, and the server uses IPSec NAT-T, unintended side effects may occur because of the way that network address translators translate network traffic
If you put a server behind a network address translator, you may experience connection problems because clients that connect to the server over the Internet require a public IP address. To reach servers that are located behind network address translators from the Internet, static mappings must be configured on the network address translator. For example, to reach a Windows Server 2003-based computer that is behind a network address translator from the Internet, configure the network address translator with the following static network address translator mappings:

• Public IP address/UDP port 500 to the server's private IP address/UDP port 500.
• Public IP address/UDP port 4500 to the server's private IP address/UDP port 4500.
These mappings are required so that all Internet Key Exchange (IKE) and IPSec NAT-T traffic that is sent to the public address of the network address translator is automatically translated and forwarded to the Windows Server 2003-based computer
Is it possible to do implicit transitive forest to forest trust relation ship in windows 2003?
Implicit Transitive trust will not be possible in windows 2003. Between forests we can create explicit trust
Two-way trust
One-way: incoming
One-way: Outgoing
GPMC & RSOP in windows 2003?
GPMC is tool which will be used for managing group policies and will display information like how many policies applied, on which OU’s the policies applied, What are the settings enabled in each policy, Who are the users effecting by these polices, who is managing these policies. GPMC will display all the above information.

RSoP provides details about all policy settings that are configured by an Administrator, including Administrative Templates, Folder Redirection, Internet Explorer Maintenance, Security Settings, Scripts, and Group Policy Software Installation.
When policies are applied on multiple levels (for example, site, domain, domain controller, and organizational unit), the results can conflict. RSoP can help you determine a set of applied policies and their precedence (the order in which policies are applied).

Assign & Publish the applications in GP & how?
Through Group policy you can Assign and Publish the applications by creating .msi package for that application
With Assign option you can apply policy for both user and computer. If it is applied to computer then the policy will apply to user who logs on to that computer. If it is applied on user it will apply where ever he logs on to the domain. It will be appear in Start menu—Programs. Once user click the shortcut or open any document having that extension then the application install into the local machine. If any application program files missing it will automatically repair.
With Publish option you can apply only on users. It will not install automatically when any application program files are corrupted or deleted.


How to use recovery console?
The Windows 2000 Recovery Console is a command-line console that you can start from the Windows 2000 Setup program. Using the Recovery Console, you can start and stop services, format drives, read and write data on a local drive (including drives formatted to use NTFS), and perform many other administrative tasks. The Recovery Console is particularly useful if you need to repair your system by copying a file from a floppy disk or CD-ROM to your hard drive, or if you need to reconfigure a service that is preventing your computer from starting properly. Because the Recovery Console is quite powerful, it should only be used by advanced users who have a thorough knowledge of Windows 2000. In addition, you must be an administrator to use the Recovery Console.

There are two ways to start the Recovery Console:
If you are unable to start your computer, you can run the Recovery Console from your Windows 2000 Setup disks or from the Windows 2000 Professional CD (if you can start your computer from your CD-ROM drive).
As an alternative, you can install the Recovery Console on your computer to make it available in case you are unable to restart Windows 2000. You can then select the Recovery Console option from the list of available operating systems
PPTP protocol for VPN in windows 2003?
Point-to-Point-Tunneling Protocol (PPTP) is a networking technology that supports multiprotocol virtual private networks (VPN), enableing remote users to access corporate networks securely across the Microsoft Windows NT® Workstation, Windows® 95, and Windows 98 operating systems and other point-to-point protocol (PPP)-enabled systems to dial into a local Internet service provider to connect securely to their corporate network through the Internet
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.
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
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
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

what is the role responsible for time synchronization
PDC Emulator is responsible for time synchronization. Time synchronization is important because Kerberos authentication depends on time stamp information

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
How to take DNS and WINS,DHCP backup
%System root%/system32/dns
%System root%/system32/WINS
%System root%/system32/DHCP
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

How to monitor replication
We can user Replmon tool from support tools
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
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.
what is the protocol used for terminal services
RDP
what is the port number for RDP
3389

What are the port numbers?
FTP-21, Telnet – 23, HTTP-80, SMTP-25, TFTP-69, TCP-6, UDP-17, DNS-53, Kerberos-88, LDAP-389, DHCP-67, 68, IP V6-41, RIP-520, ICMP-1, IGRP-9,
Global Catalog-3268, Pop3-110, Terminal Server-RDP-3389

what are the different types of profiles in 2000
Local Profiles
Roaming profiles
Mandatory Profiles
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