VMWare and Windows

VMware Storage I/O Control - VMware SIOC

2016-01-05T14:47:00.001+05:30

SIOC is considered to be one of the finest addition to the VMware feature stack. In this blog we will discuss about SIOC and its impact on Disk usage.

Before discussing about SIOC, we should understand the relevance of VM based 'Disk Shares' in VMware. The disk share concept is simple and much alike Memory and CPU shares. When there is a resource constraint, the host will throttle the disk usage of VMs by adjusting its Disk Queue Depth based on its share values. If all the VMs have the same Disk Share, the control over disk will be shared among all VMs. If the share value of a VM is high, it gets precedence over other VMs.

Simple and effective right...then why should VMware introduce a new feature called Storage I/O Control - SIOC.

The answer is simple, 'Disk Share' calculates the share value of VMs in a particular host whereas the relevance of SIOC comes in a cluster.

SIOC is configured for a particular datastore and will be disabled by default. Once enabled, SIOC gets active based on the value of the datastore latency. The current latency of datastore will be stored in the file called iormstat.sf which is hidden in the datastore. The default threshold value of latency is set to 30ms which is of course configurable. The threshold value can be changed based on the underlying storage technology. For eg: <20 and="" for="" ms="" nbsp="" sata.="" span="" ssd="">SIOC requires VMware Enterprise Plus license.

A datastore-wide disk scheduler (PARDA control algorithm) runs on each host sharing that datastore. This scheduler will be triggering 'Latency computation' and 'Window Size Computation' algorithms. 'Latency Computation' is used to detect if SIOC needs to throttle queues to ensure each VM gets its fair share. 'Window Size Computation' is used to calculate what this queue depth should be for your host. Once the queue depth is calculated by PARDA, the 'Local Host Scheduler' will take on from there. By default the queue depth is 32 and will be adjusted to a value calculated by PARDA which will be always higher than 4.

VMware recommends that this feature should be enabled for better VM performance. It is not at all advisable to leave a datastore unconfigured with SIOC, when other datastores in the same physical array is configured with SIOC.

Pictorial representation of SIOC scenario

Suppose we have 3 VMs with equal disk shares of 1000 each. 2 VMs are in one ESXi and the 3rd VM in another ESXi. When SIOC is disabled, even though all VMs are configured with equal shares, the VM in the 2nd ESXi will enjoy more disk shares during resource constraint.

SIOC disabled

With SIOC enabled, VMs across hosts enjoys a fair share.

SIOC enabled

VMware converter error: Unable to create a VSS snapshot of the source volume

2016-01-05T14:45:00.003+05:30

Issue

VMware P2V conversion of Windows 2003 server fails with the below error :

FAILED : Unable to create a VSS snapshot of the source volume(s). Error code:
2147754774 (0x80042316)

Cause

This is a known issue with Microsoft and occurs when there is an issue with Windows Volume Shadow Copy Service (VSS).

Resolution

Re-register Windows Volume Shadow Copy Service (VSS) to resolve this issue.

Steps to re-register VSS (From Microsoft article):

1. Click Start, click Run, type cmd, and then click OK.

2. Type the following commands at a command prompt. Press ENTER after you type each command.

cd /d %windir%\system32
Net stop vss
Net stop swprv
regsvr32 ole32.dll
regsvr32 oleaut32.dll
regsvr32 vss_ps.dll
vssvc /register
regsvr32 /i swprv.dll
regsvr32 /i eventcls.dll
regsvr32 es.dll
regsvr32 stdprov.dll
regsvr32 vssui.dll
regsvr32 msxml.dll
regsvr32 msxml3.dll
regsvr32 msxml4.dll

Note The last command may not run successfully.

3. Rerun the converter.

Note : This article is not for use with Windows Vista, with Windows Server 2008, or with later operating systems. Starting with Windows Vista and with Windows Server 2008, Windows component installation is manifest based. If you try to manually register specific components, such as those that are described in this "Resolution" section, in the operating systems that are mentioned in this note, unexpected results may occur that may require reinstalling Windows to resolve.

VMware vMotion error at 14% - Scene 2

2016-01-05T14:43:00.001+05:30

Issue

While performing vMotion, the operation fails at 14% with the below error :

vMotion migration [-1062731490:1419235061251156] failed to create a connection with remote host : The ESX hosts failed to connect over the VMotion network
Migration [-1062731490:1419235061251156] failed to connect to remote host <Destination vMotion IP> from host : Network unreachable
The vMotion failed because the destination host did not receive data from the source host on the vMotion network. Please check your vMotion network settings and physical network configuration and ensure they are correct.

Resolution

I've already penned a post on VMware vMotion failure at 14%. This blog is an extended version of that post. If none of the steps mentioned in my previous post helped you, then you are in the right page.

Check whether vMotion is selected for multiple vmkernel NICs in ESXi host. !!!!

If yes, make only one NIC available for vMotion.

IP/Networking Commands

2015-12-07T16:41:00.005+05:30

There are a lot of IP commands with short descriptions listed here but you should only need the ones mentioned here at the top of the page to diagnose and configure your network.

C:>ping
C:>ipconfig
C:>ipconfig /all
C:>ipconfig /release
C:>ipconfig /renew
C:\>nbtstat –a

Remember when typing from the command prompt you can only type one command per line, and press Enter after each one to execute it.

C:\>arp –a: is short for address resolution protocol, It will show the IP address of your computer along with the IP address and MAC address of your router.

C:\>hostname: This is the simplest of all TCP/IP commands. It simply displays the name of your computer.

C:\>ipconfig: The ipconfig command displays information about the host (the computer your sitting at)computer TCP/IP configuration.

C:\>ipconfig /all: This command displays detailed configuration information about your TCP/IP connection including Router, Gateway, DNS, DHCP, and type of Ethernet adapter in your system.

C:\>Ipconfig /renew: Using this command will renew all your IP addresses that you are currently (leasing) borrowing from the DHCP server. This command is a quick problem solver if you are having connection issues, but does not work if you have been configured with a static IP address.

C:\>Ipconifg /release: This command allows you to drop the IP lease from the DHCP server.

C:\>ipconfig /flushdns: This command is only needed if you’re having trouble with your networks DNS configuration. The best time to use this command is after network configuration frustration sets in, and you really need the computer to reply with flushed.

C:\>nbtstat –a: This command helps solve problems with NetBIOS name resolution. (Nbt stands for NetBIOS over TCP/IP) Definitions

C:\netdiag: Netdiag is a network testing utility that performs a variety of network diagnostic tests, allowing you to pinpoint problems in your network. Netdiag isn’t installed by default, but can be installed from the Windows XP CD after saying no to the install. Navigate to the CD ROM drive letter and open the support\tools folder on the XP CD and click the setup.exe icon in the support\tools folder.

C:\>netstat: Netstat displays a variety of statistics about a computers active TCP/IP connections. This tool is most useful when you’re having trouble with TCP/IP applications such as HTTP, and FTP.

C:\>nslookup: Nslookup is used for diagnosing DNS problems. If you can access a resource by specifying an IP address but not it’s DNS you have a DNS problem.

C:\>pathping: Pathping is unique to Window’s, and is basically a combination of the Ping and Tracert commands. Pathping traces the route to the destination address then launches a 25 second test of each router along the way, gathering statistics on the rate of data loss along each hop.

C:\>ping: Ping is the most basic TCP/IP command, and it’s the same as placing a phone call to your best friend. You pick up your telephone and dial a number, expecting your best friend to reply with “Hello” on the other end. Computers make phone calls to each other over a network by using a Ping command. The Ping commands main purpose is to place a phone call to another computer on the network, and request an answer. Ping has 2 options it can use to place a phone call to another computer on the network. It can use the computers name or IP address.

C:\>route: The route command displays the computers routing table. A typical computer, with a single network interface, connected to a LAN, with a router is fairly simple and generally doesn’t pose any network problems. But if you’re having trouble accessing other computers on your network, you can use the route command to make sure the entries in the routing table are correct.

C:\>tracert: The tracert command displays a list of all the routers that a packet has to go through to get from the computer where tracert is run to any other computer on the internet.

Important TCP /IP commands in windows

2015-12-07T16:29:00.000+05:30

To day am going to tel you few simple networking commands to keep

keep track ip journey.

Commands:

1. tracert
2. netstat
3. nslookup

1.tracert:

Tracert (traceroute) is another command adopted from Unix system. When ever you try
to open any website from your computer.We request our computer to go to that website
IP address by hopping into a few router address and fetch the website for you,tracert
is networking command and which is used to track hopping path.

PROCEDURE:

1.Open Command prompt and type cmd.

2.In command prompt simply type tracert sitename

From the above picture you can see it your trying to trace Google routing path from
your computer it has taken 12 router paths. and It differs with internet speed.

2.netstat:

Netstat displays the active TCP connections and ports on which the computer is listening, Ethernet statistics, the IP routing table, statistics for the IP, ICMP, TCP, and UDP protocols. Netstat also can be used to tracking your outbound or inbound connection to your computer, it’s useful to malicious connection. Let’s see the picture below to see the available switch in netstat.

PROCEDURE:

1.Open Command prompt and type cmd.

2.In command prompt simply type netstat

In above picture you can see all active networking connections.You can also find which
port correctly listings.type following command.

netstat -np TCP | find "80"

3.nslookup:

This command helps to diagnose the Domain Name System (DNS) infrastructure and comes with a number of sub-commands. Usually used by hackers to find out some useful information that you can’t find on search engine. In this tips and trick I’m only show you how to find server IP address or host name. Type nslookup and the enter the URL of website you want to know it’s IP address for example I use Google.

PROCEDURE:

1.Open Command prompt and type cmd.
2.In command prompt simply type nslookup
3.Type website name.

In above image you can see Google actually using couple of address. Google can be pinged
from any of above address.

10 Useful Windows Commands You Should Know

2015-12-07T16:19:00.006+05:30

There are some things you can only do from the command line, even on Windows. Some of these tools don’t have graphical equivalents, while others are just plain faster to use than their graphical interfaces.

We can’t possibly cover all the useful commands you can use in the Command Prompt or PowerShell here. We’ll be focusing on commands that should be useful even if you’re not a command-line person.

ipconfig – Quickly Find Your IP Address

You can find your IP address from the Control Panel, but this takes quite a few clicks. The ipconfig command is a fast way of determining your computer’s IP address and other information, such as the address of its default gateway — useful if you want to know the IP address of your router’s web interface.

To use the command, just type ipconfig into a Command Prompt window. You’ll see a list of all the network connections your computer is using. Look under Wireless LAN adapter if you’re connected to Wi-Fi or Ethernet adapter Local Area Connection if you’re connected to a wired network.

ipconfig /flushdns – Flush Your DNS Resolver Cache

If you change your DNS server, the effects won’t necessarily take place immediately. Windows uses a cache that remembers DNS responses it’s received, saving time when you access the same addresses again in the future.

To ensure Windows is getting addresses from the new DNS servers instead of using old, cached entries, run the ipconfig /flushdns command after changing your DNS server.

ping, tracert – Troubleshoot Network Connection Issues

If you’re experiencing issues connecting to a website or other network connection issues, Windows and other operating systems have some standard tools you can use to identify problems.

First, there’s the ping command. Type ping google.com and Windows will send packets to Google.com. Google will respond and let you know it’s received them. You’ll be able to see if any packets didn’t make it to Google.com — perhaps you’re experiencing packet loss — and how long it took you to hear back — perhaps the network is saturated and packets are taking a while to reach their destinations.

There’s also the tracert command, which traces the route it takes for a packet to reach a destination. For example, run tracert google.com and you’ll see the path your packet takes to reach Google. If you’re having issues connecting to a website, tracert can show you where the problem is occurring.

For more information about using these commands, read our introduction to troubleshooting Internet connection problems.

shutdown – Create Shutdown Shortcuts on Windows 8

The shutdown command is particularly useful on Windows 8. You can use it to create your own shortcuts and place them on your Start screen or desktop, allowing you to more easily shut down Windows without digging through the charms bar or logging out first.

This command can also be used to restart your computer. On Windows 8, you can even use a special switch to restart your computer into the advanced startup options menu.

Shut Down: shutdown /s /t 0
Restart: shutdown /r /t 0
Restart Into Startup Options: shutdown /r /o

recimg – Create Custom Recovery Images

The Refresh Your PC feature on Windows 8 allows you to restore your computer’s system state to its original state — either from a clean Windows install or as the computer came from its manufacturer. You can create your own custom recovery images, but this feature is hidden — you have to do it with the recimg command from a command line. This allows you to removemanufacturer-installed bloatware or add your favorite desktop programs to your recovery image.

For more information about using recimg, read our overview of everything you need to know about creating and using custom recovery images on Windows 8.

wbadmin start backup – Create System Recovery Images

Windows 8.1 removes the Windows 7 backup interface, which allowed you to create system backup images. These system images contain a complete snapshot of every single file on the system, so they’re different from Windows 8’s recovery images.

While the graphical interface has been removed, system administrators and geeks can still create system image backups by running the wbadmin start backup cmdlet in a PowerShell window. Unlike all the other commands here, this command-line tool must be run from within PowerShell, not the Command Prompt.

sfc /scannow – Scan System Files for Problems

Windows includes a system file checker tool that scans its system files and looks for problems. If system files are missing or corrupted, the system file checker will repair them. This may fix problems with some Windows systems.

To use this tool, open a Command Prompt window as Administrator and run the sfc /scannowcommand.

telnet – Connect to Telnet Servers

The telnet client isn’t installed by default. You’ll have to install it from the Control Panel. Once installed, you can use the telnet command to connect to telnet servers without installing any third-party software.

You should avoid using telnet if you can help it, but if you’re connected directly to a device and it requires that you use telnet to set something up — well, that’s what you have to do.

cipher – Permanently Delete and Overwrite a Directory

The cipher command is mostly used for managing encryption, but it also has an option that will write garbage data to a drive, clearing its free space and ensuring no deleted file can be recovered. Deleted files normally stick around on disk unless you’re using a solid state drive. The cipher command effectively allows you to “wipe” a drive without installing any third-party tools.

To use the command, specify the drive you want to wipe like so:

ciper /w:C:\

netstat -an – List Network Connections and Ports

The netstat command is particularly useful, displaying all sorts of network statistics when used with its various options. One of the most interesting variants of netstat is netstat -an, which will display a list of all open network connections on their computer, along with the port they’re using and the foreign IP address they’re connected to.

This isn’t a comprehensive list of all the commands you might find useful, but we hope it’s given you some idea of the many powerful tools lurking under the surface. Linux isn’t the only operating system where users can benefit from learning some commands.

Windows print server

2015-04-21T13:04:00.000+05:30

1. What is windows print server?
Ans – A print server, or printer server, is a device that connects printers to client computers over a network. It accepts print jobs from the computers and sends the jobs to the appropriate printers.

2.How does a window print server work?
Ans – Normally, a server operating system is installed on the print server computer and then the office’s various printers can be added to the system with the appropriate drivers. The new printers are then set up to be shared from the print server, so that employees can access them from their individual workstations.

3.What is print spooling?
Ans – In print spooling, documents are loaded into a buffer (usually an area on a disk), and then the printer pulls them off the buffer at its own rate. Because the documents are in a buffer where they can be accessed by the printer, you can perform other operations on the computer while the printing takes place in the background. Spooling also lets you place a number of print jobs on a queue instead of waiting for each one to finish before specifying the next one.

4.What is windows universal print driver?
Ans – (Universal Printer Driver or Unidriver) is a GDI-based Microsoft Windows universal printer driver and architecture for non-PostScript printers. It is used to simplify driver development of non-PostScript printers (also called Winprinters) for printer manufacturers. Unidrv allows the creation of a printer-specific minidriver in the form of a GPD (Generic Printer Description) file, similar to a PPD file, which is much simpler than kernel mode driver development.

5.What is a XPS and EMF print drivers?
Ans – Universal XPS Printer driver -
This driver is based on the Windows XML Paper Specification (XPS) printing technology introduced in Windows Server 2008. Windows XPS printing technology uses XML to create a platform-independent “electronic paper” similar to Adobe’s PDF format. The XPS format is a device-independent XML-based spool file format that provides a compressed XML description of a page’s graphic elements. Printing devices can use XPS-formatted print jobs directly without translation.
The Citrix Universal XPS Printer driver creates the XPS print job using the Microsoft XPS printer driver on the client device. The Citrix Universal XPS Printer driver obtains printing device-specific information from the client device. Provided your farm servers are running XenApp 5.0 and your client devices have .NET 3.0 installed on them, which comes with Windows
Vista, you can use the Citrix Universal XPS Printer driver.
Citrix Universal Printer driver -
This driver uses Windows’ Enhanced Metafile Format (EMF) technology.EMF is a device-independent format for capturing the graphical elements printed on each page of a print job. A client-side renderer uses EMF and provides a substantial reduction in the processing time of Citrix Universal print jobs on the client.

Windows 2003 vs Windows 2008

2015-04-16T18:01:00.000+05:30

1) Windows 2003 vs Windows 2008

§ Full and Core Installation-Windows 2008 gives you two installation types, Full installation and Server Core installation which helps to reduce the cost of the hardware for instance if have a requirement to install only DNS or DHCP server to particular location or site. then you can choose core installation and install DNS or DHCP, it can be installed on low hardware resources machine as it would not install unnecessary Drivers and roles that requires for enhanced GUI. However, It wasn’t available in windows 2003.

§ Operating System Installation is faster- Windows server 2008 Installation is faster because it’s 32 bit where as 2003 it is 16 bit. It deploys the image of operating system rather than coping the files in 2003.

§ Changes in RIS- Windows deployment services (WDS) instead of RIS in 2003 server

§ Service is renamed to Role -Services are known as role in windows server 2008, like Active Directory has been renamed to Active Directory DomainServices (AD DS)

§ Changes in Boot sequence- Windows server 2008 Boot sequence is changed

§ Virtualization- Hyper-V is the main difference between windows 2003 and windows 2008

§ PowerShell- PowerShell been fully supported, you can manage easily using PowerShell script and PowerShell commands

§ Active Directory- There are many changes in Active Directory like Active Directory is a service now that can be restarted. RODC is a new type of DC introduce in windows 2008. Group policy preference mode is introduced. New number of AD templates have been introduced in 2008. DFS is being used for replication instead of FRS in 2003.

§ Security- Windows basic security has been Improved, features like Bitlocker

§ Windows Cluster – There are many new feature been introduced in windows 2008 cluster like new quorum types and GPT disk support

§ DNS – There are some new features been introduced in DNS 2008

§ Disk Management – Disk Management has more features like Extend and Shrink feature that Administrator can used to increase or decrease the Existing volumes Disk space more accurately and easily.

§ Print Server – In Windows 2008 Print Server will give enhanced admin management experience like you can install Drivers remotely from any other windows machine through Print Management snap-in. Print administrator delegation is also a new feature of windows 2008 R2

§ Power Saving Feature – New power-saving features been introduced in windows server 2008. It includes updated support for Advanced Configuration and Power Interface (ACPI) processor power management (PPM) features, including support for processor performance states (P-states) and processor idle sleep states on multiprocessor systems. These features can be managed through Group Policies.

§ Hardware Compatibility – Windows Server 2008 can support more Hardware than 2003.

2) FSMO Roles

In this post let's talk about the FSMO Roles. As we all know Active Directory is a Multi Master Replication
Model. Means Clients can register their records in any available Active Directory Domain Controller as well as they can access resources within Active Directory NTDS.Dit Database. Before you learn how to transfer FSMO Roles you must have a better understating why do we use FSMO roles, the answer is to avoid Conflicts in Active Directory . In old day there was only single master Replication. Primary DNS used
to have a read and write copy of DNS Data, Means Client Must locate their DNS Server and register their
resources in order to locate all other resources in Active Directory Domain Infrastructure. The main Drawback of Single Master Replication was single point of failure. If in case the Primary DNS was not reachable Clients Could not Register it's records to other domain Controller. Primary zone is forward look up zone in AD. And it's highly recommended to have reverse look up zone in all size of Network because it contains host names and IP Mapping Information.
So the Main purpose of FSMO roles is to avoid conflicts in AD and if there is any changes and update in AD FSMO Roles will take of it accordingly. We have Five Roles in FSMO

1: Schema Master
2:Domain Naming Master
3:Infrastructure Master
4:RID(Relative ID) Master
5: PDC Emulator Master

1: Schema Master: This role is forest wide role and it is responsible for any update and medication or if there is any changes in Schema. Once the update is complete it will replicate these updates to other domain
controllers in the forest. There can be only one schema master in the whole forest.

2:Domain Naming Master: This is also a Forest wide Role. And it is responsible for if there is any addition and Removal of Domain in the Forest.When you create a new domain in an existing forest, the new domain represents a separate naming context and a new Cross-Ref object must be created in a Partitions container. As we know only one Domain Naming Master is allowed to make changes in Partition Container
in the forest . By default first Domain Controller in the forest would hold this role however you can transfer this to other domain Using Active Directory Domain and Trust in.

3:Infrastructure Master Role: This role is responsible for updating the objects SID and distinguish name in cross domain object references. as it is domain wide role there can be only one domain controller acting as the infrastructure master in each domain.

4:RID(Relative ID) : All object in Active Directory Domain have a Security Identifier (SID) which is a combination of Domain ID and sequential number called Relative ID which is supplied by Relative ID. It is a domain wide role. In Domains that are in Default in windows server 2000 mixed domain functional level only PDC Emulator create Security Principle. That's the reason RID and PDC Emulator are held by a domain controller so that it can ensure that SID is unique and sequential.

5:PDC Eumlator: PDC Emulator has a very unique Role. you might have seen in the offices when you Enter your user name and password which you have been provided by Administrator you are logged on , In some cases you might have seen you get an error message which says invalid user name and password. Have you ever thought how do you get that error message . when you enter the wrong user name and password domain controller checks for the password and for the confirmation it sends user's credential to the PDC Emulator. Because PDC Emulator contains the latest information about the objects credentials . if it finds that user has entered the wrong user name and password then user gets an error message on the screen invalid user name and password. when an Administrator change or reset the password those information are updated at the same time in PDC Emulator.
Apart from this PDC Emulator perform other task as well. I believe now you have the better knowledge of FSMO Roles now you will learn how to transfer the FSMO roles.

Microsoft Outlook Questions

2015-03-24T16:20:00.000+05:30

1. What is the difference between Microsoft Outlook and Microsoft Outlook express?

Outlook Express is primarily an email client and new group 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 categorise their friends for example, but a business will categorise their contacts. Outlook will store electronic business cards, while Express cannot. If you have a slower internet connection or slow computer go for Outlook express else go to the advanced version of OE with more features that is MS outlook. You can also consider going for mozilla thunderbird.

THE DIGITAL SIGNATURE OF THE OBJECT DID NOT VERIFY CORRECTLY

2015-03-17T16:32:00.001+05:30

FIXING VISUAL STUDIO 2013 INSTALLATION ERROR: VISUAL STUDIO CORE FEATURES “THE DIGITAL SIGNATURE OF THE OBJECT DID NOT VERIFY CORRECTLY”

Posted on | November 20, 2013 | No Comments

When installing Visual Studio 2013 on Windows 8.1 you might encounter some problems during the process, one of them stating that the digital signature of some components could not be verified.I did the following steps to fix the problem and afterwards successfully installed Visual Studio:

Update Windows 8.1
Try the methods from 1 to 6 stated in the following page: http://support.microsoft.com/kb/822798
Download Visual Studio as a web installer e.g. Visual Studio Ultimate: http://go.microsoft.com/?linkid=9832436&clcid=0x409
Run Visual Studio setup from the location that was stated in the Web Installer. By default: C:\Users\(Your username)\Documents\Microsoft Visual Studio Ultimate 2013\

This procedure worked for me!

VMware scenario based interview questions

2015-03-17T12:55:00.000+05:30

vMotion failed at 14%. What could be the possible reasons ?

Issue

While performing vMotion, the operation fails at 14% with the below error :

A general system error occurred: Migrtion to host failed with erro Connection closed by remote host, possibly due to timeout (0xbad003f).

Migrate virtual machine:A general system error occurred: Migration to host failed with error Connection closed by remote host, possibly due to timeout (0xbad003f).

vMotion migration [-1062729272:1406020861428172] (19-71629048648008) failed to receive...

Scenarios

Scenario 1: Your management network and vmotion network are in the same subnet using the same physical NIC.

Consider the case, where the management network and vmotion network are in the same subnet and you have assigned a VLAN id to the vMotion network, the operation fails at 14%.

My first point will be to avoid using same IP subnet for both management and vmotion networks. Because if you use the same subnet, all the vmotion traffic will be forwarded to the physical NIC connected to the management network. This is because, by default all traffic from vmkernel portgroups from the same subnet will be forwarded to the first NIC configured in the ESXi for that IP subnet. Obviously this will be the management network.

And if you still stick to the plan of using same subnet, please make sure that you have not assigned any VLAN id to the vMotion portgroup.

What happens when we assign a VLAN to the vMotion portgroup ? vMotion vmknic will try to communicate with the default gateway and since the default gateway is not tagged with the VLAN id you choose for vMotion, the operation fails.

Scenario 2: Your management network and vmotion network are in the same subnet using different physical NIC (may be using different vswitches as well).

The comments in the above scenario applies to this scenario also. It doesn't matter if you have created a new vSwitch or a new portgroup or a dedicated physical NIC for the vmotion network, if your management network is in the same subnet, do not assign a VLAN id to the portgroup.

Scenario 3: Your management network and vmotion network in different subnet.

In this case you need to check the physical switch configuration.

2. How to extend a logical volume in Windows 2003 hosted in VMware ?

Scenario

You have a single vmdk file of 200 GB and it has two logical volumes C & D with 100 GB each. Suppose you need to add another 100 GB to the D drive making it 200 GB. What would you do ?

The steps are simple and straight forward.

Change the VMDK size using vSphere client to 300 GB (Exisiting 200 GB + required space).

Log in to the VM and ensure that the added disk space is available to the VM as 'Unallocated' space
Execute the below commands in command prompt

diskpart
list volume
select volume
extend

3. CentOS Network interface is not detecting after VMware clone ?

Symptom:

Eth0 interface will not be present for a Centos VM after cloning. Only the loopback networking interface will be available. If you try to turn up the interface manually (using the command ifup eth0 or ifup-eth0), you will receive the below error.

Device eth0 does not seem to be present, delaying initialisation

Root Cause:

When you clone a Centos VM from a template, a new NIC card will be created for the cloned VM. In other terms, a new MAC address will be generated for the NIC of the cloned machine. This change happens only in VMware perspective and no modification is made in Centos. Therefore the kernel will be still searching for the NIC with old MAC address and hence fails.

Resolution:

1. Update the exisiting ethernet configuration file to reflect the new MAC address.

Check the new MAC address using vSphere client and modify the ifcfg-eth0 interface configuration using the command:

vi /etc/sysconfig/networking/devices/ifcfg-eth0

Replace HWADDR with the new MAC address

2. Remove the kernel's networking interface rules file

rm -f /etc/udev/rules.d/70-persistent-net.rules

3. Reboot the VM

4.SQL servers hosted in VMs are facing performance degradation. How to confirm whether it is a SQL related issue or VMware related issue ?

Active Directory FSMO Roles

2015-03-16T13:11:00.001+05:30

Flexible Single Master Operation Roles (FSMO)

Active Directory has five special roles which are vital for the smooth running of AD as a multimaster system. Some functions of AD require there is an authoritative master to which all Domain Controllers can refer to. These roles are installed automatically and there is normally very little reason to move them, however if you de-commission a DC and DCPROMO fails to run correctly or have a catastrophic failure of a DC you will need to know about these roles to recover or transfer them to another DC.

The forest wide roles must appear once per forest, the domain wide roles must appear once per domain.

The Roles

There are five FSMO roles, two per forest, three in every Domain. A brief summary of the role is below.

Forest Wide Roles:

Schema Master

The schema is shared between every Tree and Domain in a forest and must be consistent between all objects. The schema master controls all updates and modifications to the schema.

Domain Naming

When a new Domain is added to a forest the name must be unique within the forest. The Domain naming master must be available when adding or removing a Domain in a forest.

Domain Wide Roles:

Relative ID (RID) Master

Allocates RIDs to DCs within a Domain. When an object such as a user, group or computer is created in AD it is given a SID. The SID consists of a Domain SID (which is the same for all SIDs created in the domain) and a RID which is unique to the Domain.

When moving objects between domains you must start the move on the DC which is the RID master of the domain that currently holds the object.

PDC Emulator

The PDC emulator acts as a Windows NT PDC for backwards compatibility, it can process updates to a BDC.

It is also responsible for time synchronising within a domain.

It is also the password master (for want of a better term) for a domain. Any password change is replicated to the PDC emulator as soon as is practical. If a logon request fails due to a bad password the logon request is passed to the PDC emulator to check the password before rejecting the login request.

Infrastructure Master

The infrastructure master is responsible for updating references from objects in its domain to objects in other domains. The global catalogue is used to compare data as it receives regular updates for all objects in all domains.

Any change to user-group references are updated by the infrastructure master. For example if you rename or move a group member and the member is in a different domain from the group the group will temporarily appear not to contain that member.

Important Note :

Unless there is only one DC in a domain the Infrastructure role should not be on the DC that is hosting the global catalogue. If they are on the same server the infrastructure master will not function, it will never find data that is out of date and so will never replicate changes to other DCs in a domain.

If all DCs in a domain also host a global catalogue then it does not matter which DC has the infrastructure master role as all DCs will be up to date due to the global catalogue.

Viewing and Transferring Roles

The roles can be viewed and transferred in the GUI or from the command line.

Gui View

Schema Master

To view the schema you must first register the schema master dll with Windows. To do this enter the following in the RUN dialog of the start menu.

regsvr32 schmmgmt.dll

Once you have done this the schema master mmc snap-in will be available.

Active Directory Domains and Trusts

The Domain naming master can be viewed and transferred from here.

Active Directory User and Computers

The RID, PDC emulator and Infrastructure master roles can be viewed and transferred from here.

NTDSUTIL

NTDSUTIL provides FSMO maintenance and the option to seize a role (covered in the FSMO Role Failure section below).

To transfer a role using ntdsutil use the example below as a template for all the roles.

Open a command prompt
Enter in ntdsutil
At the ntdsutil command prompt enter in roles
At the fsmo maintenance prompt enter in connection
At the server connections prompt enter in connect to domancontrollername
At the server connections prompt enter in quit
At the fsmo maintenance prompt enter in transfer schema master
Quit from the console

FSMO Role Failure

Some of the operations master roles are essential for AD functionality, others can be unavailable for a while before their absence will be noticed. Normally it is not the failure of the role, but rather the failure of the DC on which the role is running.

If a DC fails which is a role holder you can seize the role on another DC, but you should always try and transfer the role first.

Before seizing a role you need to asses the duration of the outage of the DC which is holding the role. If it is likely to be a short outage due to a temporary power or network issue then you would probably want to wait rather than seize the role.

Schema Master Failure

In most cases the loss of the schema master will not affect network users and only affect Admins if modifications to the schema are required. You should however only seize this role when the failure of the existing holder is considered permanent.

Note: A DC whose schema master role has been seized should never be brought back online

Domain Naming Master Failure

Temporary loss of this role holder will not be noticeable to network users. Domain Admins will only notice the loss if they try and add or remove a domain in the forest. You should however only seize this role when the failure of the existing holder is considered permanent.

Note: A DC whose schema master role has been seized should never be brought back online

RID Master Failure

Temporary loss of this role holder will not be noticeable to network users. Domain Admins will only notice the loss if a domain they are creating objects in runs out of relative IDS (RIDs). You should however only seize this role when the failure of the existing holder is considered permanent.

Note: A DC whose schema master role has been seized should never be brought back online

PDC Emulator Master Failure

Network users will notice the loss of the PDC emulator. If the DC with this role fails you may need to immediately seize this role. Only pre Windows 2000 clients and NT4 BDCs will be affected.

If you seize the role and return the original DC to the network you can transfer the role back.

Infrastructure Master Failure

Temporary loss of this role holder will not be noticeable to network users. Administrators will not notice the role loss unless they are or have recently moved or renamed large numbers of accounts.

If you are required to seize the role do not seize it to a DC which is a global catalogue server unless all DCs are global catalogue servers.

If you seize the role and return the original DC to the network you can transfer the role back.

Tech Abbreviations

2015-03-08T12:19:00.002+05:30

ADS - Active Directory Services
ADSL - Asymmetric Digital Subscriber
APIPA - Automatic Private IP (Internet Protocol) Addressing
BSOD - Blue Screen of Death
CAT (5/6) - Category (cables)
CSMA/CD - Carrier Sense Multiple Access/Collision Detection
DC - Domain Controller
DHCP - Dynamic Host Configuration Protocol
DNS - Domain Name System
FAT32 - File Allocation Table
FSMO - Flexible Single Master Operator
FTP - File Transfer Protocol
GC - Global Catalog
GPO - Group Policy Object
GUI - Graphical User Interface
GUID - Globally Unique IDentifier
HDD - Hard Disk Drive
HTML - Hypertext Markup Language
HTTP - Hypertext Transfer Protocol
IMAP - Internet Message Access Protocol
IP - Internet Protocol
KCC - Knowledge Consistency Checker
LAN - Local Area Network
LDAP - Lightweight Directory Access Protocol
LDS - Lightweight Directory Services
MAC - Media Access Control
NAT - Network Address Translation
NNTP - Network News Transfer Protocol
NTFS - New Technology File System
NTLM - NT LAN Manager
OSI - Open Source Initiative
OST - Offline Storage Table
PDC - Primary Domain Controller
POP3 - Post Office Protocol v3
PST - Personal Storage Table / Packet Switching Technology
RAID - Redundant Array of Independent Disks
RAS - Remote Access Service
RIS - Remote Intallation Services
RPC - Remote Procedure Call
SCSI - Small Computer System Interface
SMTP - Simple Mail Transfer Protocol
SSL - Secure Socket Layer
TCP/IP - Transmission Control Protocol/Internet Protocol
URL - Universal Resource Locator
USB - Universal Serial Bus
VLAN - Virtual Local Area Network
VPN - Virtual Private Network
WAN - Wide Area Network

VMWare Interview Questions & Tips

2015-03-08T11:59:00.001+05:30

VMkernel

The VMkernel is the liaison between virtual machines (VMs) and the physical hardware that supports them. VMware calls VMkernel a microkernel because it runs on bare metal, directly on VMware ESX hosts. The VMkernal is responsible for allocating memory, scheduling CPUs and providing other hardware abstraction and operating system (OS) services.

VMware resource pool

A VMware resource pool is the aggregated physical compute hardware -- CPU and memory, as well as other components -- allocated to virtual machines (VMs) in a VMware virtual infrastructure. The VMware resource pool manages and optimizes these physical resources for virtual systems within a VMware Distributed Resource Scheduler (DRS) cluster. With memory overcommit, more resources can be allocated to VMs than are physically available. Changes that occur in one resource pool will not affect other, unrelated resource pools VMware administrators create.

VMware DRS (Distributed Resource Scheduler)

VMware DRS (Distributed Resource Scheduler) is a utility that balances computing workloads with available resources in a virtualized environment. The utility is part of a virtualization suite called VMware Infrastructure 3.
With VMware DRS, users define the rules for allocation of physical resources among virtual machines. The utility can be configured for manual or automatic control. Resource pools can be easily added, removed or reorganized. If desired, resource pools can be isolated between different business units. If the workload on one or more virtual machines drastically changes, VMware DRS redistributes the virtual machines among the physical servers. If the overall workload decreases, some of the physical servers can be temporarily powered-down and the workload consolidated.
Other features of VMware DRS include:

Dedicated infrastructures for individual business units
Centralized control of hardware parameters
Continuous monitoring of hardware utilization
Optimization of the use of hardware resources as conditions change
Prioritization of resources according to application importance
Downtime-free server maintenance
Optimization of energy efficiency
Reduction of cooling costs.

VMware Topics Index :

1. VMWare Kernel is a Proprietary Kenral and is not based on any of the UNIX operating systems, it's a kernel developed by VMWare Company.

2. The VMKernel can't boot it by itself, so that it takes the help of the 3rd party operating system. In VMWare case the kernel is booted by RedHat Linux operating system which is known as service console.

3. The service console is developed based up on Redhat Linux Operating system, it is used to manage the VMKernel

4. To restart webaccess service on vmware

service vmware-webaccess restart – this will restart apache tomcat app

5. To restart ssh service on vmware

service sshd restart

6. To restart host agent(vmware-hostd) on vmware esx server
service mgmt-vmware restart

7. Path for the struts-config.xml
/usr/lib/vmware/webAccess/tomcat/apache-tomcat-5.5.17/webapps/ui/WEB-INF/

8. To start the scripted install the command is
esx ks=nfs:111.222.333.444:/data/KS.config ksdevice=eth0
location device name

9. Virtual Network in Simple……………….

Virtual Nic(s) on Virtual Machine(s) ----->

Physical Nic on the ESX Server (Virtual Switch - 56 Ports) ----->

Physical Switch Port Should be trunked with all the VLANS to which the VM's need access

All the ESX servers should be configured with Same number of Physical Nics (vSwitches) and Connectivity also should be same, So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS, this means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on the Physical Switch Port

10 What are the three port groups present in ESX server networking
   1. Virtual Machine Port Group - Used for Virtual Machine Network
   2. Service Console Port Group - Used for Service Console Communications
   3. VMKernel Port Group - Used for VMotion, iSCSI, NFS Communications

11. What is the use of a Port Group?
The port group segregates the type of communication.

12. What are the type of communications which requires an IP address for sure ?
Service Console and VMKernel (VMotion and iSCSI), these communications does not happen without an ip address (Whether it is a single or dedicated)

13. In the ESX Server licensing features VMotion License is showing as Not used, why?
Even though the license box is selected, it shows as "License Not Used" until, you enable the VMotion option for specific vSwitch

14. How the Virtual Machine Port group communication works ?
All the vm's which are configured in VM Port Group are able to connect to the physical machines on the network. So this port group enables communication between vSwitch and Physical Switch to connect vm's to Physical Machine's

15. What is a VLAN ?
A VLAN is a logical configuration on the switch port to segment the IP Traffic. For this to happen, the port must be trunked with the correct VLAN ID.

16. Does the vSwitches support VLAN Tagging? Why?
Yes, The vSwitches support VLAN Tagging, otherwise if the virtual machines in an esx host are connected to different VLANS, we need to install a separate physical nic (vSwitch) for every VLAN. That is the reason vmware included the VLAN tagging for vSwitches. So every vSwitch supports upto 1016 ports, and BTW they can support 1016 VLANS if needed, but an ESX server doesn’t support that many VM’s. :)

17. What is Promiscuous Mode on vSwitch ? What happens if it sets to Accept?
If the promiscuous mode set to Accept, all the communication is visible to all the virtual machines, in other words all the packets are sent to all the ports on vSwitch
If the promiscuous mode set to Reject, the packets are sent to inteded port, so that the intended virtual machine was able to see the communication.

18. What is MAC address Changes ? What happens if it is set to Accept ?
When we create a virtual machine the configuration wizard generates a MAC address for that machine, you can see it in the .vmx (VM Config) file. If it doesn't matches with the MAC address in the OS this setting does not allow incoming traffic to the VM. So by setting Reject Option both MAC addresses will be remains same, and the incoming traffic will be allowed to the VM.

19. What is Forged Transmits ? What happens if it is set to Accept ?
When we create a virtual machine the configuration wizard generates a MAC address for that machine, you can see it in the .vmx (VM Config) file. If it doesn't matches with the MAC address in the OS this setting does not allow outgoing traffic from the VM. So by setting Reject Option both MAC addresses will be remains same, and the outgoing traffic will be allowed from the VM.

20. What are the core services of VC ?
VM provisioning , Task Scheduling and Event Logging

21. Can we do vMotion between two datacenters ? If possible how it will be?
Yes we can do vMotion between two datacenters, but the mandatory requirement is the VM should be powered off.

22. What is VC agent? and what service it is corresponded to? What are the minimum req's for VC agent installation ?
VC agent is an agent installed on ESX server which enables communication between VC and ESX server.
The daemon associated with it is called vmware-hostd , and the service which corresponds to it is called as mgmt-vmware, in the event of VC agent failure just restart the service by typing the following command at the service console

" service mgmt-vmware restart "
VC agent installed on the ESX server when we add it to the VC, so at the time of installtion if you are getting an error like " VC Agent service failed to install ", check the /Opt size whether it is sufficient or not.

23. How can you edit VI Client Settings and VC Server Settings ?
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configuration to Change VC Settings

24. What are the files that make a Virtual Machine ?
     .vmx - Virtual Machine Configuration File
     .nvram - Virtual Machine BIOS
     .vmdk - Virtual Machine Disk file
     .vswp - Virtual Machine Swap File
     .vmsd - Virtual MAchine Snapshot Database
     .vmsn - Virtual Machine Snapshot file
     .vmss - Virtual Machine Suspended State file
     .vmware.log - Current Log File
     .vmware-#.log - Old Log file

25. What are the devices that can be added while the virtual Machine running
In VI 3.5 we can add Hard Disk and NIC's while the machine running.

In vSphere 4.0 we can add Memory and Processor along with HDD and NIC's while the machine running

26. How to set the time delay for BIOS screen for a Virtual Machine?
Right Click on VM, select edit settings, choose options tab and select boot option, set the delay how much you want.

27. What is a template ?
We can convert a VM into Template, and it cannot be powered on once its changed to template. This is used to quick provisioning of VM's.

23. What to do to customize the windows virtual machine clone,?
copy the sysprep files to Virtual center directory on the server, so that the wizard will take the advantage of it.

24. What to do to customize the linux/unix virtual machine clone,?
VC itself includes the customization tools, as these operating systems are available as open source.

25. Does cloning from template happens between two datacenters ?
Yes.. it can, if the template in one datacenter, we can deploy the vm from that template in another datacenter without any problem.

26. What are the common issues with snapshots? What stops from taking a snapshot and how to fix it ?
If you configure the VM with Mapped LUN's, then the snapshot failed. If it is mapped as virtual then we can take a snapshot of it.
If you configure the VM with Mapped LUN's as physical, you need to remove it to take a snapshot.

27. What are the settings that are taken into to consideration when we initiate a snapshot ?
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)

28. What are the requirements for Converting a Physical machine to VM ?
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plug-in
A server to import/export virtual machines

29. What is VMWare consolidated backup ?
It is a backup framework, that supports 3rd party utilities to take backups of ESX servers and Virtual Machines. Its not a backup service.

30. To open the guided consolidation tool, what are the user requirements ?
The user must be member of administrator, The user should have "Logon as service" privileges - To give a user these privileges, open local sec policy, select Logon as service policy and add the user the user should have read access to AD to send queries

What is a Hypervisor?

There are two types of virtualization software's available from vmware. One works at application level (ex. vmware workstation & vmware server) and the other one works at Operating system level (ex.VMWare ESX server, Microsoft Hype-V, Citrix XenServer etc. These are called Hypervisors. The Hypervisor is an operating system/virtualization which directly communicate with the hardware and provides better access of resources to the virtual machines. Where as i said before, virtualization apps like vmware workstation, microsoft virtual server, vmware server will provide access of resources to virtual machines through Operating system, as those are dependent on OS and are residing at application level. So, with the help hypervisor we can take the advantage of extra-ordinary resource allocation and management. With the Hypervisor, the architecture looks like below

What is vMotion?

Moving a virtual machine from an ESX host to another while it is running. You will get a very minimum downtime for the virtual machine with this if everything configured properly. If you want to do some maintenance tasks on one ESX server in the cluster, you can vMotion all the virtual machines running on it to other ESX server which has the enough resources available. Instead of giving lot of explanation for this topic, lets see this video from VMware, i bet you will definitely become a fan of VMware with this video. :)

How to fix HA errors in VMware ESX Server?

1. Make sure all the hosts in the cluster are able to resolve each other by host name.

2. If they were not able to do so, check the DNS settings.

3. Best solution is to add all the hosts names and ip addresses into /etc/hosts file on all ESX servers in the cluster. Put the ESX server in maintenance mode before doing any changes.

4. Exit from the maintenance mode and try to reconfigure the HA on all the ESX hosts one by one, that's it your problem will be fixed.

What is VMware Consolidated Backup?

VMware Consolidate Backup is a Backup framework developed by VMware company. It is installed on Windows Server box as a proxy. Using the third party backup tools like Veritas Netbackup, Veeam Backup software's we can take backup’s of the virtual machines hosted on the ESX hosts. In detail VMware Consolidate Backup is used as mediator between the backup software and Virtual machines / ESX hosts.

It enables the backup operators to take the backup at file level from the .vmdk files, and also enables to take snapshots. And one more important future is, its a LAN free backup solution, as the Backup Proxy server is directly connected to SAN environment (which is used by those esx hosts and virtual machines).

How it is Used?

1. As you see in the image, the backup proxy (Windows server with VM Consolidated Backup & Backup Agent) server is directly connected to the SAN.

2. The Backup agent (for ex: Veritas Netbackup / Veeam Backup) initiates the backup request through VMware Consolidated Backup, it immediately takes a snapshot of the VM from the SAN storage and mounts the .vmdk file on the proxy server and takes the backup of the files inside the .vmdk

3. Those files are stored on to a tape drive / backup disk.

4. The main advantage of this framework is, no backup agent needs to be installed on the VM’s or ESX servers. And as it is a LAN free backup, there is no need of bringing down any of these.

Basically, here is how VCB works:

If you are doing a file level backup, VCB does a snapshot of the VM, mounts the snapshot, and allows you to backup that mounted "drive" through VCB to your 3rd party backup software
If you are doing an image level backup of the VM, VCB does a snapshot of the VM, copies the snapshot to the VCB server, unsnaps the VM, and allows you to backup the copied snapshot image with your 3rd party backup software.

Unable to power on the Virtual Machine, How to fix it?

If the virtual machine is running in a cluster of esx hosts, some times it won’t power on. Why because, the files that are associated with that VM are locked by the host at the time of running. So when you try to vmotion the vm from one host to another host, the first host releases those files and again locked by the second host.

So what is meant by locking here, and why it is happening?

Locking is nothing but, the registration of a vm with a host. this happens everytime when the vm is hosted on a host. this is helpful to prevent the access to the same vm for remaining hosts in the cluster.

Why the vm fails when trying to power it on?

When the files associated with that VM are locked by a host it won’t powered on. At that time, you must unregister the vm from the host using vmware-cmd utility

VMware Storage VMotion : Virtual Machine Relocation

In this article I would like to discuss about the new and outstanding technology i.e “Storage VMotion”. Till now we heard about What is VMotion? How it Happens?. With that knowledge we are going forward to learn about this new feature in vSphere. Storage VMotion is similar to VMotion in means of migrating Virtual Machine from one location to another with out downtime or without disturbance in the services. When we initiate VMotion the reference of the Virtual Machine moves from one host to another host, but not the data which is related to that VM. With Storage VMotion reference of the Virtual Machine remains in the same location, but the data moves from one location (storage) to another location (storage).

Let’s check this out how it works….

VMware Storage VMotion allows virtual machine storage disks to be relocated to different datastore locations with no downtime, while being completely transparent to the virtual machine or the end user.

Before moving a virtual machines disk file, Storage VMotion moves the “home directory” of the virtual machine to the new location. The home directory contains meta data about the virtual machine (configuration, swap and log files). After relocating the home directory, Storage VMotion copies the contents of the entire virtual machine storage disk file to the destination storage host, leveraging “changed block tracking” to maintain data integrity during the migration process. Next, the software queries the changed block tracking module to determine what regions of the disk were written to during the first iteration, and then performs a second iteration of copy, where those regions that were changed during the first iteration copy (there can be several more iterations).

Once the process is complete, the virtual machine is quickly suspended and resumed so that it can begin using the virtual machine home directory and disk file on the destination datastore location. Before VMware ESX allows the virtual machine to start running again, the final changed regions of the source disk are copied over to the destination and the source home and disks are removed. This approach guarantees complete transactional integrity and is fast enough to be unnoticeable to the end user.

Storage VMotion facilitates us to do Storage Upgrades / Maintenance & supports to optimize the storage performance with out downtime. The best advantage of Storage VMotion is we can efficiently utilize our storage resources.

VMFS

VMware uses a file system called VMFS, which has extensive support to the clustering in VMware Environment. And also supports futures like VMotion, DRS, RDM, Snapshots etc. Here i have provided some of the Features and Limitations of Virtual Machine File Systems. This is used by all the virtual machines, and apart from this every virtual machine has its own file system like Windows VM has NTFS, Linux VM has ext2/3 FS etc. So in conclusion i can say like a file system which gives support to another file system.

Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking. SCSI Reservations are only implemented when LUN meta data is updated (e.g. file name change, file size change, etc.)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts.
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS volume on the fly (by spanning multiple VMFS volumes)
With ESX/ESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine I/O with adjustable volume, disk, file and block sizes.
Recover virtual machines faster and more reliably in the event of server failure with Distributed journaling.
Limitations
Can be shared with up to 32 ESX Servers.
Can support LUN's with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere).
"There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers. For instance, if there is a tree of disks off the same base disk with 40 leaf nodes in the tree, all 40 leaf nodes can be simultaneously run but they can only run on up to 8 ESX hosts."
VMFS-3 limits files to 262,144 (218) blocks, which translates to 256 GB for 1 MB block sizes (the default) up to 2 TB for 8 MB block sizes

FC SAN (Fiber Channel Storage Area Network) : It is the most efficient way to provide storage to the Virtual Environment. If you want to read more about SAN, please. In this technology (FC SAN), HBA cards and Optical Fiber Cables are used to Access the storage. The storage is access in the form of Blocks. And as we are using Optical Fiber cables for communication the data transfer speed is very high. VMware has limited support to the HBA cards, only some specific models are supported by VMware. The storage is allocated in the form of LUNS( A specific size of space taken from different number of hard disks) , and these LUN’s will have a unique address which is called as WWN (World wide number) and the same used to access the LUN from the ESX Server/VM.

iSCSI SAN : It is another way of accessing the storage. In this technology the same LUN’s created and allocated for ESX server and VM’s. But the way communication is done using the Ethernet cards and RJ45 Cables. Here the identification of storage is IPaddress. It is very easy to configure and as most of the Ethernet cards are supported by VMware there is a good scope in using iSCSI SAN. And the data transfer speed is reasonable so as the Cost to implement is also very less when compared to FC SAN.

NFS ( Network File System) : This is a future of UNIX Operating Systems. You can create a NFS share in a UNIX server and the same can be made available to the ESX Server to store the virtual machines. This communication is done the same way of our regular network communication. You just need to provide the NFS share path to the ESX server in storage options, so that it will be mounted and comes available to ESX Server.

RDM (Raw Device Mappings) : Generally when we create a Virtual Machine we will create/allocate some space to the .vmdk file which is used as the internal hard disk for the Virtual Machine. We can create/allocate space for .vmdk file from the above 3 storage types. But those cannot be directly accessed by the Virtual Machine. First ESX server accesses it and it passes that access to the Virtual Machine. But using RDM we can give direct access to the Virtual Machine to the above said storages. But one disadvantage of RDM is we cannot take snapshots if we configure it as Physical.

What is SAN? How the basic SAN environment look like ?

SAN : (Storage Area Network) A network of storage disks. In large enterprises, a SAN connects multiple serversto a centralized pool of disk storage. Compared to managing hundreds of servers, each with their own disks, SANs improve system administration. By treating all the company's storage as a single resource, disk maintenance and routine backups are easier to schedule and control. In some SANs, the disks themselves can copy datato other disks for backup without any processing overhead at the host computers.

In the above image you are able to see the basic SAN setup in larger enterprises. I will explain it now how the connectivity goes between all the devices.

What are the devices that are needed for a SAN setup?

1. SAN BOX (San Device) – It contains more number of disks to accommodate required storage to the other servers in the environment.

2. SAN NETWORK SWITCH – SAN switches are similar to normal switches but their functionality is to process storage traffic.

3. HBA CARD : Host Bus Adapter is an interface card as NIC which resides in the normal server to initiate storage requests.

4. OPTICAL FIBER CABLES or RJ45 CABLES : For Communication

How the communication goes now?

1. To assign more storage to the server, first it should have the HBA cards installed in it as well as the the storage devices are also comes with HBA cards by default.

2. These HBA cards are connected to SAN switch using Optical/RJ45 cables from both ends.

3. Storage engineer creates LUN’s and allocates them to servers. Those LUN are identified by the LUN numbers. Before that, every HBA card is having its own WWN (World Wide Number) as MAC address. It is used in giving right/read access to these LUN’s. (Logical Unit Numbers) A LUN is created from an array of hard disks. It will be in any of the size.

4. Once the LUN’s are visible to the server, they can be mounted on to it in different ways because every OS has its own process to mount the LUN’s. After mounting the LUN’s they are visible as LOCAL DISKS on the server (but they ar coming from the storage area network).

5. One important point is, in FC SAN’s the data is accessible as BLOCKS with a max speed of 4MBPS, and in iSCSI SAN’s the data is accessible as files with a max speed of 1MBPS.

6. The FC SAN is very costly when compared to iSCSI SAN, because Optical Fiber Cable is used in it instead of RJ45 cable. This is the reason the transfer speed is very high. One advantage of iSCSI than FC SAN is that, it can be accessible from anywhere in the world as it relies on IP for communication as same as normal network. And its very difficult to connect the storage boxes across the world using the Fibre Cable. One it is very costly and it doesn’t rely upon IP. Even though the speed is low in iSCSI SAN, but it is the only one that is preferable in Wide Area Networks.

Cloud Computing Amazon Interview Questions and Answers

2015-03-07T20:37:00.004+05:30

How does cloud computing provides on-demand functionality?
Cloud computing is a metaphor used for internet. It provides on-demand access to virtualized IT resources that can be shared by others or subscribed by you. It provides an easy way to provide configurable resources by taking it from a shared pool. The pool consists of networks, servers, storage, applications and services.

What is the difference between scalability and elasticity?
Scalability is a characteristic of cloud computing through which increasing workload can be handled by increasing in proportion the amount of resource capacity. It allows the architecture to provide on demand resources if the requirement is being raised by the traffic. Whereas, elasticity is being one of the characteristic provide the concept of commissioning and decommissioning of large amount of resource capacity dynamically. It is measured by the speed by which the resources are coming on demand and the usage of the resources.What are the different layers of cloud computing?
Cloud computing consists of 3 layers in the hierarchy and these are as follows:
1. Infrastructure as a Service (IaaS) provides cloud infrastructure in terms of hardware like memory, processor speed etc.
2. Platform as a Service (PaaS) provides cloud application platform for the developers.
3. Software as a Service (SaaS) provides cloud applications which are used by the user directly without installing anything on the system. The application remains on the cloud and it can be saved and edited in there only.
What resources are provided by infrastructure as a service?
Infrastructure as a Service provides physical and virtual resources that are used to build a cloud. Infrastructure deals with the complexities of maintaining and deploying of the services provided by this layer. The infrastructure here is the servers, storage and other hardware systems.
How important is platform as a service?
Platform as a Service is an important layer in cloud architecture. It is built on the infrastructure model, which provides resources like computers, storage and network. This layer includes organizing and operate the resources provided by the below layer. It is also responsible to provide complete virtualization of the infrastructure layer to make it look like a single server and keep it hidden from the outside world.
What does software as a service provide?
Software as Service is another layer of cloud computing, which provides cloud applications like google is doing, it is providing google docs for the user to save their documents on the cloud and create as well. It provides the applications to be created on fly without adding or installing any extra software component. It provides built in software to create wide varieties of applications and documents and share it with other people online.
What are the different deployment models?
Cloud computing supports many deployment models and they are as follows:
- Private Cloud
Organizations choose to build there private cloud as to keep the strategic, operation and other reasons to themselves and they feel more secure to do it. It is a complete platform which is fully functional and can be owned, operated and restricted to only an organization or an industry. More organizations have moved to private clouds due to security concerns. Virtual private cloud is being used that operate by a hosting company.
- Public Cloud
These are the platforms which are public means open to the people for use and deployment. For example, google, amazon etc. They focus on a few layers like cloud application, infrastructure providing and providing platform markets.
- Hybrid Clouds
It is the combination of public and private cloud. It is the most robust approach to implement cloud architecture as it includes the functionalities and features of both the worlds. It allows organizations to create their own cloud and allow them to give the control over to someone else as well.
What are the different datacenters deployed for this?
Cloud computing is made up of various datacenters put together in a grid form. It consists of different datacenters like:
- Containerized Datacenters
These are the traditional datacenters that allow high level of customization with servers, mainframe and other resources. It requires planning, cooling, networking and power to access and work.
- Low-Density Datacenters
These datacenters are optimized to give high performance. In these datacenters the space constraint is being removed and there is an increased density. It has a drawback that with high density the heat issue also creeps in. These datacenters are very much suitable to develop the cloud infrastructure.
What is the use of APIï¿½s in cloud services?
API stands for Application programming interface is very useful in cloud platforms as it allows easy implementation of it on the system. It removes the need to write full fledged programs. It provides the instructions to make the communication between one or more applications. It also allows easy to create application with ease and link the cloud services with other systems.
What are the different modes of software as a service?
Software as a Service provides cloud application platform on which user can create application with the tools provided. The modes of software as a service are defined as:
1. Simple multi-tenancy: in this each user has its own resources that are different from other users. It is an inefficient mode where the user has to put more time and money to add more infrastructure if the demand rises in less time to deliver.
2. Fine grain multi-tenancy: in this the functionality remains the same that the resources can be shared to many. But it is more efficient as the resources are shared not the data and permission within an application.
What is the security aspects provided with cloud?
Security is one of the major aspects which come with any application and service used by the user. Companies or organizations remain much more concerned with the security provided with the cloud. There are many levels of security which has to be provided within cloud environment such as:
- Identity management: it authorizes the application service or hardware component to be used by authorized users.
- Access control: permissions has to be provided to the users so that they can control the access of other users who are entering the in the cloud environment.
- Authorization and authentication: provision should be made to allow the authorized and authenticated people only to access and change the applications and data.
What is the difference between traditional datacenters and cloud?
Cloud computing uses the concept of datacenter as it is the datacenter is based on the tradition one so the difference between them are as follows:
– Cost of the traditional datacenter is higher, due to heating issues and other hardware/software related issues but this is not the case with the cloud computing infrastructure.
– It gets scaled when the demand increases. Most of the cost is being spent on the maintenance being performed on the datacenters, whereas cloud platform requires minimum maintenance and not very expert hand to handle them.
What are the three cost factors involves in cloud data center?
Cloud data center doesn’t require experts to operate it, but it requires skilled people to see the maintenance, maintain the workloads and to keep the track of the traffic. The labor cost is 6% of the total cost to operate the cloud data center. Power distribution and cooling of the datacenter cost 20% of the total cost. Computing cost is at the end and is the highest as it is where lots of resources and installation has to be done. It costs the maximum left percentage.
How the cloud services are measured?
Cloud computing provides the services to the organizations so they can run their applications and install them on the cloud. Virtualization is used to deploy the cloud computing models as it provides a hidden layer between the user and the physical layer of the system. The cloud services are measured in terms of use. Pay as much as you use that can be on the basis of hours or months or years. Cloud services allow users to pay for only what they use and according to the demand the charges or the prices gets increased.
What are the optimizing strategies used in cloud?
To optimize the cost and other resources there is a concept of three-data-center which provides backups in cases of disaster recovery and allows you to keep all the data intact in the case of any failure within the system. System management can be done more efficiently by carrying out pre-emptive tasks on the services and the processes which are running for the job. Security can be more advanced to allow only the limited users to access the services.
What are different data types used in cloud computing?
Cloud computing is going all together for a different look as it now includes different data types like emails, contracts, images, blogs, etc. The amount of data increasing day by day and cloud computing is requiring new and efficient data types to store them. For example if you want to save video then you need a data type to save that. Latency requirements are increasing as the demand is increasing. Companies are going for lower latency for many applications.
What are the security laws which take care of the data in the cloud?
The security laws which are implements to secure data in the cloud are as follows: Input validation: controls the input data which is being to any system. Processing: control that the data is being processed correctly and completely in an application. File: control the data being manipulated in any type of file. Output reconciliation: control the data that has to be reconciled from input to output. Backup and recovery: control the security breaches logs and the problems which has occurred while creating the back.
How to secure your data for transport in cloud?
Cloud computing provides very good and easy to use feature to an organization, but at the same time it brings lots of question that how secure is the data, which has to be transported from one place to another in cloud. So, to make sure it remains secure when it moves from point A to point B in cloud, check that there is no data leak with the encryption key implemented with the data you sending.
What do you understand from VPN?
VPN stands for virtual private network; it is a private cloud which manages the security of the data during the transport in the cloud environment. VPN allows an organization to make a public network as private network and use it to transfer files and other resources on a network.
What does a VPN consists of?
VPN is known as virtual private network and it consists of two important things:
1. Firewall: it acts as a barrier between the public network and any private network. It filters the messages that are getting exchanged between the networks. It also protects from any malicious activity being done on the network.
2. Encryption: it is used to protect the sensitive data from professional hackers and other spammers who are usually remain active to get the data. With a message always there will be a key with which you can match the key provided to you.
Name few platforms which are used for large scale cloud computing
There are many platforms available for cloud computing but to model the large scale distributed computing the platforms are as follows:
1. MapReduce: is software that is being built by Google to support distributed computing. It is a framework that works on large set of data. It utilizes the cloud resources and distributes the data to several other computers known as clusters. It has the capability to deal with both structured and non-structured data.
2. Apache Hadoop: is an open source distributed computing platform. It is being written in Java. It creates a pool of computer each with hadoop file system. It then clusters the data elements and applies the hash algorithms that are similar. Then it creates copy of the files that already exist.
What are some examples of large cloud providers and their databases?
Cloud computing has many providers and it is supported on the large scale. The providers with their databases are as follows:
- Google bigtable: it is a hybrid cloud that consists of a big table that is spilt into tables and rows. MapReduce is used for modifying and generating the data.
- Amazon SimpleDB: is a webservice that is used for indexing and querying the data. It allows the storing, processing and creating query on the data set within the cloud platform. It has a system that automatically indexes the data.
- Cloud based SQL: is introduced by Microsoft and it is based on SQL database. it provides data storage by the usage of relational model in the cloud. The data can be accessed from the cloud using the client application.
What are some open source cloud computing platform databases?
Cloud computing platform has various databases that are in support. The open source databases that are developed to support it is as follows:
1. MongoDB: is an open source database system which is schema free and document oriented database. It is written in C++ and provides tables and high storage space.
2. CouchDB: is an open source database system based on Apache server and used to store the data efficiently
3. LucidDB: is the database made in Java/C++ for data warehousing. It provides features and functionalities to maintain data warehouse.
What essential things a user should know before going for cloud computing platform?
A user should know some parameters by which he can go for the cloud computing services. The parameters are as follows:
1. User should know the data integrity in cloud computing: It is a measure to ensure integrity like the data is accurate, complete and reasonable.
2. Compliance: user should make sure that proper rules and regulations are followed while implementing the structure.
3. Loss of data: user should know about the provisions that are provided in case of loss of data so that backup and recovery can be possible.
4. Business continuity plans: user should think about does the cloud services provide him uninterrupted data resources.
5. Uptime: user should know about the uptime the cloud computing platform provides and how helpful it is for the business.
6. Data storage costs: user should find out about the cost which you have to pay before you go for cloud computing.
What are system integrators?
Systems integrators are the important part of cloud computing platform. It provides the strategy of the complicated process used to design a cloud platform. It includes well defined architecture to find the resources and the characteristics which have to be included for cloud computing. Integrators plan the users cloud strategy implementation. Integrators have knowledge about data center creation and also allow more accurate private and hybrid cloud creation.
What is the requirement of virtualization platforms in implementing cloud?
Virtualization is the basis of the cloud computing and there are many platforms that are available like VMware is a technology that provides the provision to create private cloud and provide a bridge to connect external cloud with private cloud. There are three key features that have to be identified to make a private cloud that is:
– Cloud operating system.
– Manage the Service level policies
– Virtualization keeps the user level and the backend level concepts different from each other so that a seamless environment can be created between both.
What is the use of eucalyptus in cloud computing environment?
Eucalyptus stands for Elastic Utility Computing Architecture for Linking Your Programs to Useful Systems and provides an open source software infrastructure to implement clusters in cloud computing platform. It is used to build private, public and hybrid clouds. It can also produce your own datacenter into a private cloud and allow you to extend the functionality to many other organizations. Eucalyptus provides APIs to be used with the web services to cope up with the demand of resources used in the private clouds.
Explain different layers which define cloud architecture
Cloud computing architecture consists of many layers which help it to be more organized and can be managed from one place. The layers are as follows:
1. Cloud controller or CLC is the top most level in the hirerachy which is used to manage the virtualized resources like servers, network and storage with the user APIs.
2. Walrus is used for the storage and act as a storage controller to manage the demands of the users. It maintains a scalable approach to control the virtual machine images and user data.
3. Cluster Controller or CC is used to control all the virtual machines for executions the virtual machines are stored on the nodes and manages the virtual networking between Virtual machines and external users.
4. Storage Controller or SC provides a storage area in block form that are dynamically attached by Virtual machines.
5. Node Controller or NC is at the lowest level and provides the functionality of a hypervisor that controls the VMs activities, which includes execution, management and termination of many instances.
How user will gain from utility computing?
Utility computing allow the user to pay per use means whatever they are using only for that they have to pay. It is a plug in that needs to be managed by the organizations on deciding what type of services has to be deployed from the cloud. Utility computing allows the user to think and implement the services according to them. Most organizations go for hybrid strategy that combines internal delivered services that are hosted or outsourced services.
Is there any difference in cloud computing and computing for mobiles?
Mobile cloud computing uses the same concept but it just adds a device of mobile. Cloud computing comes in action when a task or a data get kept on the internet rather then individual devices. It provides users on demand access to the data which they have to retrieve. Applications run on the remote server, and then given to the user to be able to, store and manage it from the mobile platform.

What are the different components used in AWS?

The components that are used in AWS are:
1. Amazon S3: it is used to retrieve input data sets that are involved in making a cloud architecture and also used to store the output data sets that is the result of the input.
2. Amazon SQS: it is used for buffering requests that is received by the controller of the Amazon. It is the component that is used for communication between different controllers.
3. Amazon SimpleDB: it is used to store intermediate status log and the tasks that are performed by the user/
4. Amazon EC2: it is used to run a large distributed processing on the Hadoop cluster. It provides automatic parallelization and job scheduling.

What are the uses of Amazon web services?
Amazon web services consist of a component called as Amazon S3 that acts as a input as well used as an output data store. It is used in checking the input and according to that gives the output. The input consists of the web that is stored on Amazon S3 as object and it is update frequently to make the changes in the whole architecture. It is required due to the on demand growing of the data set and to provide persistent storage.

How to use Amazon SQS?
Amazon SQS is a message passing mechanism that is used for communication between different connectors that are connected with each other. It also acts as a communicator between various components of Amazon. It keeps all the different functional components together. This functionality helps different components to be loosely coupled, and provide an architecture that is more failure resilient system.

How buffer is used in Amazon web services?
Buffer is used to make the system more resilient to burst of traffic or load by synchronizing different component. The components always receive and process the requests in unbalanced way. Buffer keeps the balance between different components and makes them work at the same speed to provide faster services.

What is the need of the feature isolation in Amazon web services?
Isolation provides a way to hide the architecture and gives an easy and convenient way to the user to use the services without any difficulty. When a message is passed between two controllers then a queue is maintained to keep the message. No controller calls any other controller directly. The communication takes place between the controllers by storing their messages in a queue. It is a service that provides a uniform way to transfer the messages between different application components. This way all the controllers are kept isolated from each other.

What is the function of a Amazon controller?
The functions that are involved with an Amazon controller are:
– Controllers are used to control the flow in which the messages between the other system components has to be passed.
– It controls the overall structure of the Amazon and all to retrieve the message, process the message, execute a function and store the message in other queue that are completely isolated from other controllers.
– It manages and monitors the messages passed between the systems.

What is the function of Amazon Elastic Compute Cloud?
Amazon Elastic compute cloud is also known as Amazon EC2 is an Amazon web service that provides scalable resources and makes the computing easier for developers. The main functions of Amazon EC2 are:
– It provides easy configurable options and allow user to configure the capacity.
– It provides the complete control of computing resources and let the user run the computing environment according to his requirements.
– It provides a fast way to run the instances and quickly book the system hence reducing the overall time.
– It provides scalability to the resources and changes its environment according to the requirement of the user.
– It provides varieties of tools to the developers to build failure resilient applications.

What are the different types of instances used in Amazon EC2?
The instances that can be used in Amazon EC2 are:
1. Standard Instances: It provides small instances, large instances, extra large instances that give various configuration options from low range to very high range like Computing power unit, memory, processor, etc.
2. Micro Instances: It provides small consistent resources like CPU, memory and computing unit. It provides the resources to the applications that consume less amount of computing unit.
3. High Memory Instances: It provides large memory sizes for high end application and it includes memory caching applications as well.

What are cluster compute instances?
The cluster compute instances consist of the high CPU with network performance and are suited with high end applications. It provides network bound application and provide extra large computing resources like 23 GB memory, 33.5 EC2 compute units. It provide general purpose graphics unit to allow user with high end configuration. It also provide highly parallelized processing application that user can use and modify the server accordingly.

How to use SimpleDB with Amazon?
Every architecture rely on a database that is easy to maintain and gets easily configured Amazon uses the database by the name SimpleDB. This is the database that is used for cloud architecture to track the statuses of the components. The component of the system are asynchronous and discrete, it requires capturing the state of the system so that in any failure the user can easily revert back to its normal configuration. SimpleDB is schema-less database and there is no need to define the structure before the creation of any data. Every controller in the database defines their own structure and link the data to a job.

How does component services used for Amazon SimpleDB?
Component services allow the controllers to independently store the states of the virtual machines and the database that is in use. It creates asynchronous highly available services. It stores active requests according to the unique ID that are associated with each system. It stores the status of the entire database that is having different states for different components in a log database file.

How to upload files in Amazon S3?
Amazon S3 provides uploading of large files and retrieve small offsets for end-to-end transfer data rates. The large file gets stored into small files that are smaller in size. Amazon S3 stores multiple of files together in a bundle or in a compressed form for example in .gzip or .gz format and then convert them into Amazon S3 objects. The files get uploaded on the Amazon server by the use of FTP or another protocol and then retrieved through the HTTP GET request. The request includes the defined parameters like URL, offset (byte-range) and size (length).

What is the use of multi-threaded fetching in Amazon S3?
– Multi-threading fetching in Amazon S3 is used to fetch the objects concurrently using the multiple threads and map the task so that fetching can be made simpler.
– It is not a good practice to increase the threading for a particular object as every node on the server has some bandwidth constraints.
– It provides user the ease with which they can upload the files and upload the threads in parallel.
– It provides high speed of data transfer and easy maintenance of the sever as well.

What is the difference between on demand and reserved instances?
– On demand instance allow user to pay for the computing capacity according to their use every hour, whereas reserved instances provide user to pay for every instance which they use and they want to reserve.
– On demand instance provide user a free working environment in which there is no need for too much of planning related to complexities, whereas reserved instances provide user with discounts on the hourly charge of an instance and provide a easy way to manage the instances as well.
– On demand instance provide maintenance of hardware and transforms fixed cost into much smaller variable costs, whereas reserved instance provide easy way to balance the pay package.

What are the provisions provided by Amazon Virtual Private cloud?
Amazon private cloud provides a provision to create a private and isolated networking infrastructure to give easily the Amazon web services. – Virtual network topologies define the traditional data-center approach to control and mange the files from one place.
– It provides complete control over IP address range, creation of sub-nets and configuring the network gateways and route tables.
– It provides easy to customize network configuration like creation of public sub-net to access the Internet easily.
– It allow to create multiple security layers and provide network control list by which you can control the access to Amazon EC2 instances.

Windows Server DHCP Interview Questions

2015-03-07T19:59:00.000+05:30

1. What is dhcp ?

Dynamic Host Configuration Protocol (DHCP) is a network protocol that enables a server to automatically assign an IP address to a computer from a defined range ofnumbers (i.e., a scope) configured for a given network.

2. What is the dhcp process for client machine?

1. A user turns on a computer with a DHCP client.

2. The client computer sends a broadcast request (called a DISCOVER or DHCPDISCOVER), looking for a DHCP server to answer.

3. The router directs the DISCOVER packet to the correct DHCP server.

4. The server receives the DISCOVER packet. Based on availability and usage policies set on the server, the server determines an appropriate address (if any) to give to the client. The server then temporarily reserves that address for the client and sends back to the client an OFFER (or DHCPOFFER) packet, with that address information. The server also configures the client’s DNS servers, WINS servers, NTP servers, and sometimes other services as well.

5. The client sends a REQUEST (or DHCPREQUEST) packet, letting the server know that it intends to use the address.

6. The server sends an ACK (or DHCPACK) packet, confirming that the client has a been given a lease on the address for a server-specified period of time.

3. What is dhcp scope ?

DHCP scopes are used to define ranges of addresses from which a DHCP server can assign IP addresses to clients.

4. Types of scopes in windows dhcp ?

Normal Scope – Allows A, B and C Class IP address ranges to be specified including subnet masks, exclusions and reservations. Each normal scope defined must exist within its own subnet.

Multicast Scope – Used to assign IP address ranges for Class D networks. Multicast scopes do not have subnet masks, reservation or other TCP/IP options.

Multicast scope address ranges require that a Time To Live (TTL) value be specified (essentially the number of routers a packet can pass through on the way to its destination).

Superscope – Essentially a collection of scopes grouped together such that they can be enabled and disabled as a single entity.

5. What is Authorizing DHCP Servers in Active Directory ?

If a DHCP server is to operate within an Active Directory domain (and is not running on a domain controller) it must first be authorized.

This can be achieved either as part of the DHCP Server role installation, or subsequently using either DHCP console or at the command prompt using the netsh tool.

If the DHCP server was not authorized during installation, invoke the DHCP console (Start -> All Programs -> Administrative Tools -> DHCP),

right click on the DHCP to be authorized and select Authorize. To achieve the same result from the command prompt, enter the following command:

netsh dhcp server serverID initiate auth

In the above command syntax, serverID is replaced by the IP address or full UNC name of system on which the DHCP server is installed.

6. What ports are used by DHCP and the DHCP clients ?

Requests are on UDP port 68, Server replies on UDP 67 .

7. List some Benefits of using DHCP

DHCP provides the following benefits for administering your TCP/IP-based network:

Safe and reliable configuration.DHCP avoids configuration errors caused by the need to manually type in values at each computer. Also, DHCP helps prevent address conflicts caused by a previously assigned IP address being reused to configure a new computer on the network.

Reduces configuration management.

Using DHCP servers can greatly decrease time spent to configuring and reconfiguring computers on your network. Servers can be configured to supply a full range of additional configuration values when assigning address leases. These values are assigned using DHCP options. Also, the DHCP lease renewal process helps assure that where client configurations need to be updated often (such as users with mobile or portable computers who change locations frequently), these changes can be made efficiently and automatically by clients communicating directly with DHCP servers.

The following section covers issues that affect the use of the DHCP Server service with other services or network configurations. Using DNS servers with DHCP Using Routing and Remote Access servers with DHCP Multihomed DHCP servers.

8. Describe the process of installing a DHCP server in an AD infrastructure ?

Open Windows Components Wizard. Under Components , scroll to and click Networking Services. Click Details . Under Subcomponents of Networking Services , click Dynamic Host Configuration Protocol (DHCP) and then click OK . Click Next . If prompted, type the full path to the Windows Server 2003 distribution files, and then click Next. Required files are copied to your hard disk.

9. How to authorize a DHCP server in Active Directory Open DHCP ?.

In the console tree, click DHCP

On the Action menu, click Manage authorized servers.

The Manage Authorized Servers dialog box appears. Click Authorize.

When prompted, type the name or IP address of the DHCP server to be authorized, and then click OK.

10. What is DHCPINFORM?

DHCPInform is a DHCP message used by DHCP clients to obtain DHCP options. While PPP remote access clients do not use DHCP to obtain IP addresses for the remote access connection, Windows 2000 and Windows 98 remote access clients use the DHCPInform message to obtain DNS server IP addresses, WINS server IP addresses, and a DNS domain name.

The DHCPInform message is sent after the IPCP negotiation is concluded. The DHCPInform message received by the remote access server is then forwarded to a DHCP server. The remote access server forwards DHCPInform messages only if it has been configured with the DHCP Relay Agent.

SCCM Questions & Answers

2015-03-04T13:30:00.001+05:30

1. What is PRIMARY SITE?

Four main characteristics:

The Site has access to a Microsoft SQL Server Database
Can administer or be administered via the Configuration Manager Console
It can be a child of other Primary Sites and can have Child Sites of its own
Clients can be assigned directly to the Site

2. What is Secondary Site?

Four Main characteristics:

A Secondary Site does not have access to a Microsoft SQL Database
Secondary Sites are ALWAYS a Child Site of a Primary Site and can only be administered via a Primary Site
Secondary Sites cannot have Child Sites of their own
Clients cannot be assigned directly to the Site

3. What is CENTRAL SITE?

A Central Site is a Configuration Manager Primary Site that resides at the top of the Configuration Manager hierarchy. All Database information rolls from the child to the parent and is collected by the Central Site’s Configuration Manager Database. The Central Site can administer any site below it in the hierarchy and can send data down to those sites as well.

4. What is BITS-Enabled Distribution Points ?

Client computer always uses server message blocks (SMB) instead of BITS. Helps control bandwidth throttling between client computers and distribution points.BITS-enabled distribution point and is interrupted, it can resume where it left off.

5. What is SMS Provider ?

WMI provider that allows both read and write access to the SCCM DB. SMS Provider computer is offline, all Configuration Manager 2007 consoles for the site will not function. MS Provider is used by the Configuration Manager console, Resource Explorer.

6. What is Server Locator Point ?

SLP are used in a SCCM hierarchy to complete client site assignment on the intranet and help clients find MP when they cannot find that information through AD Domain Services.

7. What is Fallback status point ?

Site system role that helps you manage clients and identify any client-related problems.

SMS 2003 client computers cannot use a fallback status point.

Fallback client support how many client’s: 1lack

Identify clients that are unmanaged because they have problems communicating with their MP.

Here you can see that because a FSP was not defined, the state messages (100, 400) from the ccmsetup.log were not forwarded anywhere. The next set of snippets are from the ccmsetup.log where the client is passed the FSP= property during client installation.Notice that the FSP line is no longer blank and contains the FQDN of the server holding the FSP Role.

8. What is MIF ?

SCCM can use MIF files to determine the success or failure of an installation.

After a program has finished executing, SCCM will look in the %windir% and %temp% directories for new MIF files (created after the time of the program execution start) and then match them on any or all of the following criteria.

9. Why MOF Files Used by Hardware Inventory?

2 MOF files used by hardware inventory processes are the Configuration.mof and SMS_def.mof MOF files. To enable Asset Intelligence, you need to open the SMS_DEF.MOF file

Unlike the configuration.mof file, the SMS_def.mof file is never directly sent to clients.

Only the policy generated by the contents of the SMS_def.mof is actually compiled by Configuration Manager 2007 clients.SMS_def.mof file defines the reporting classes used by the hardware inventory client agent.

10. What is the differences between Package Refresh & Package Update ?

Package Update:- This should be used if you make any changes to the source files themselves. When you update a package, it will create a brand new, fully complete, compressed file (thats the PCK file located in the SMSPKG folder) and also create a delta compressed package file, which only has the changes made between the old and new compressed files. The delta files are then sent to all the DP’s and the new PCK file is then used for any new DP’s that are added to the package from then on. This also updates the source version of the package in SQL.

Package Refresh:- I normally use the refresh if either, I get any hash errors on clients trying to use the files to install software (the package has uncompressed but is corrupt) or in conjunction with the preloadpkgonsite.exe tool. No new PCK files are sent, it simply sends another PKG file, which then uses the current PCK file on the server and uncompresses the files again, overwriting the old package files.

11. Why to Extend Schema in SCCM ?

Publish the ConfigMgr 2012 site information to AD, ConfigMgr 2012 can publish information to AD.

extadsch.exe tool or the ConfigMgr_ad_schema.ldf file

4 actions are required to enable Configuration Manager Clients to query Active Directory Domain Services to locate site resources

Extend the Active Directory schema.

Create the System Management container.

Set security permissions on the System Management container.

Enable Active Directory publishing for the Configuration Manager site.

12. What is Senders?

There are two types of senders Standard Sender & Courier Sender

Standard Sender(Pre-stage Content requires Courier sender):- The standard sender is installed and configured by default on all primary and secondary sites. If your site-to-site communications occur over a LAN that uses a supported protocol, you do not need to install another sender

Courier Sender:- The courier sender is installed and configured by default on all primary and secondary sites.When you have large packages that require excessive time or bandwidth to be sent over the network, this sender can be useful. You can use courier sender at the source Configuration Manager 2007 site to create a parcel (that is, a collection of files transferred from one site to another using courier sender); write the parcel to a tape, CD, or other physical medium; and then ship the tape or CD to the destination site by mail or a courier service. At the destination site, you can then use courier sender at that site to receive the parcel and import the package data into the site.

13. What are Discovery Methods ?

Active Directory System Group Discovery

Active Directory Security Group Discovery

Active Directory System Discovery

Active Directory User Discovery

Network Discovery

Heartbeat Discovery

14. What are the Site System Roles ?

Management Point

Server locator Point

Distribution Point

Software Update Point

Reporting Point

Fallback Status Point

PXE Service Point

State Migration Point

15. SCCM BITS Throttling ?

Computer Client Agent Properties found within Site Management\Site\Site Settings\Client Agents

Group Policy Preferences to throttle BITS traffic

13. What are Ports used in SCCM ?

Client to site system 80(HTTP)and default HTTPS port 443

Site Server to Site Server SMB 445 its bi-directional

TCP 2701 is the port that SCCM 2012 used for remote control.

16. SCCM Design questions ?

The following is a list of questions that should be considered as part of any SCCM Design.

15. In case of acquiring a new SCCM Infrastructure question to be probed ?

Network Design

Who owns the network?

How many users are there at each physical site?

What is the physical and logical layout of the underlying network?

What is the speed of network links between sites?

What is the bandwidth utilization of the network links?

Is a network map available showing the various sites, how the sites are interconnected and the speed of links between sites?

Will network links be upgraded if recommended by the SCCM Design? Are any ports closed on any firewalls or other network infrastructure that SCCM will need to use?

Which subnets are used?

Does each subnet relate to a single physical location or are subnets split across physical locations?

What types of traffic are carried over the network links?

Will SCCM activities be limited to certain times of the day?

Is any compression used on the network infrastructure such as routers?

Backups

Are backups performed across the network? When?

Are backups done on SCCM Primary Site? When? Software Distribution

How many applications are used at each site and what are the usage patterns for each application?

What is the estimated number of packages deployed in each month? 1 per month, 12 per year

Are there any business critical applications?

Are there any in-house developed applications?

Are all new application requests going to use SMS as the delivery mechanism once a request has been approved?

How often are applications updated?

Security

Are there any specific security requirements?

What IT Administration model is used for each site and overall?Support Model

What are the roles and responsibilities for implementation, usage and ongoing support of SCCM?

Which users/ groups will require access to SCCM and which tasks will they need to perform?

Are the any Service Level Agreements that may affect the overall design for SCCM?

Is there anyone/ a group with SQL skills already in the customer?

Is there anyone/ a group with IIS skills already in the customer?Clients

What languages are used on the machines to be managed by SCCM?

Are there any other projects currently in progress or planned that could either have an impact on SMS or be impacted by SCCM?

Are there any pre-requisites/ dependencies that may impact the SCCM project? Are there any “remote” users that dial into the network?

Are there any users that never connect to the LAN (for example mobile users that never connect via the LAN but only via Dialup or VPN)?

SMS ImplementationAre the Site servers dedicated to SCCM are shared with other functions/ applications such as acting as a Domain Controller, File and Print Server, hosting SQL, IIS, etc?

Who owns the servers that will be used in SCCM roles?

Which Client Agents are to be enabled?

What settings are going to be used for each Client Agent?

Interview Questions for L2 Engineer in Infrastructure Management Companies

2015-03-03T18:37:00.000+05:30

Infrastructure management companies in India Like HCL, WIPRO, TCS, Microland, HP, EDS, MPHASIS, IBM, etc. Even other companies ask the below questions when recruiting a windows professional for L2 level.
================================================================================
These questions would help in the interviews conducted for positions open in Infrastructure management companies for the post of WINTEL L2 positions. These are common questions which are always asked. ================================================================================

1. How to check AD configured properly?Ans: Check NTDS and SYSVOL shared folder at %systemroot%windows\.

2. How to transfer global catalog to another domain?Ans: We can not transfer the global catalog; we can only remove the global catalog from one server and enable other server as a global catalog.

3. How to configure global catalog server?Ans: Go to Active directory site and services and expand till your desire server’s NTDS settings and then right click; property and check mark the Global catalog check box.

4. What are the fsmo roles and it gets down what will impact?
Ans: Flexible Single Master Operation, There are five roles.
Domain Naming Master (Forest wide role)
Schema Master (Forest wide role)
PDC Emulator (Domain wide role)
RID Master (Domain wide role)
Infrastructure Master (Domain wide role)

5. What is the RID pool?Ans: RID Master provides the RID (Relative Identifier) pool to Domain controller of the Domain. When an object is create in a domain, a Unique SID (Security ID) is assigned to it which consisting of a RID (Unique ID) and a SID (Common ID for all Object), A RID pool contain 500 RIDs.

6. How to check FSMO roles running on which server?
Ans: By using “DCdiag /test:Knowsofroleholders /v” command.
ii) Type “Netdom query fsmo”

7. How to transfer FSMO role one domain controller to another domain controller command prompt and GUI?Ans: Go to Start->Run->dsa.msc go the property of users and computers and transfer the RID, PDC, and Infrastructure roles.
Go to Start à Run->go to the property of the active directory domain and trust and transfer the Domain naming master role
For transferring schema master role, first we have to register the schema master by using “regsvr32 schmgmt.dll” command in run. Than Go start à Runà MMCàAdd Active directory schema and transfer the schema master role.

8. What is AD data base file and log file where it stored is and what is the use of log file?
Ans: AD Data base is NTDS.DIT and its location is %system root%\windows\NTDS\ntds.dit. AD Log files are EDB.log ,EDB.chk and REG.log and the location of there files are %system root%\windows\NTDS\ntds.dit.

9. How to recover corrupted AD data base file?
Ans: Its described very well in the article available here.

10. Is it possible to rename domain name in windows 2003?Ans: Yes, We can rename the domain name in windows 2003.

11. What are the two types of replication?
Ans: Inter-site replication, Intra-site replication.

12. What are the protocols used in replication?
Ans: RPC and SMTP. Predominantly RPC is used. SMTP is not used as its not recommended for replication of Domain Partition.

Replication conflict is managed using a method described here. Read the full article several times and you would be happy that you got to know something very important.

13. What is default time for replication?
Ans: KCC (Knowledge Consistency Checker) is the algorithm and the two protocols used are RPC over IP and SMTP over IP. They replicate in every 15 min.

14. What is the difference between the two types of replication i.e. intrasite and intersite?
Intersite replication is for replication with in the site and Intra-site replication is for the replication between the sites.

15. What are replication partition and tell about partition?
Ans: FSMO role Partition
Schema CN=Schema,CN=configuration, DC=
Domain Naming Master CN=configuration,DC=
PDC DC=
RID DC=
Infrastructure DC=
Replication partitions are.
Schema Partition
Configuration Partition
Domain Partition
Application Partition

16. Is application partition available in windows 2003?
Ans: Yes, Windows 2003 contains application partition, mainly application partition contains the application information like: DNS

17. What is the DNS?
Ans: Domain Naming System.
Used to resolve the host name (FQDN) name to IP Address and Vice Versa

18. What are types of DNS and zones?
(i)Primary DNS zone
(ii)Secondary DNS zone
(iii)Active directory integrated zone
(IV)Stub zone

To know more about DNS please read the blog http://dnsfunda.blogspot.com

19. What is the Start of Authority (SOA) record and is its use?
Ans: It contains information like the server name where the file was created (Primary DNS Server name), it Maintains the serial number and increments it after every change in the DNS Zone, stores Refresh interval and Retry interval time, maintains TTL of the records as well. Read this article for more details.

@   IN  SOA     nameserver.place.dom.  postmaster.place.dom. (
                               1            ; serial number
                               3600         ; refresh   [1h]
                               600          ; retry     [10m]
                               86400        ; expire    [1d]
                               3600 )       ; min TTL   [1h]

20. What are records available in dns?
Ans: Address records, Host Records, MX Records, and CNAME records.

21. Explain about SRV, MX and CNAME records?
ANS: SRV records point a client to the servers which are hosting a service. For example Active Directory Service. MXrecord points to the client to servers hosting mail service. MX stands for Mail Exchanger. CNAME record is a alias record for a name that already exists. Suppose there were two servers and both of them consolidated into one, in that case one name becomes useless. But any application dependent on unused name has to work, in that case we create an alias record which is the unused name pointing to the name in use. Hence the application keeps functioning.

22. Where DNS file stored and data base of DNS?
Ans: %SYSTEMROOT%\Windows\System32\DNS

23. How do I configure DHCP Server and steps?
ANS: If you have already installed DHCP on the server then follow the steps mentioned in this Trainsignal Article.

24. How to reserve IP address?Ans: We can assign a particular IP address to the MAC address of a machine using IP reservation in DHCP.

25. Why do we need two or more subnets?ANS: To segment or restrict/localize one type of traffic to one segment or subnet of the network.

26. If we have two different subnets then how do I configure it in single DHCP server?
ANS: Two different scopes are created for two subnets.

27. What is the use of relay agent?
A router drops the DHCP packet as its a broadcast packet. When we enable the relay agent option on the router it then lets the DHCP Broadcast packets pass through. Hence the relay agent helps in sending it over to the destined subnet.

28. What is the group policy?
Ans: It is way to provide the desirable predefined environment to all users in an Active Directory environment and it is centrally manageable.

29. My requirement is to need disable USB port, how will you do?
Through Group policy.

30. How to take a backup of group policy?
Ans: We can use GPMC (Group Policy Management Console), right click on the GPO and select backup and take backup on destination folder

31. You are an administrator and my requirement is to configure active directory for four different locations. How will you plan it?
Ans: Depending on the requirement I' ll configure one parent domain and three child domains, or One domain with four sites, or four different domains (least preferred).

32. What are the two modes a terminal server works in?
ANS: User mode and applciation mode.

33. What is the default security group, groups give explanations?
Ans:

34. You are maintaining remote servers that you can take remote but you can’t ping them, how to troubleshoot?

35. What is use of Kerberos protocol?
Ans: Kerberos protocol is an authentication protocol. When we login in an Active Directory environment its the protocol that is used to authenticate us.

36. What is the version Kerberos protocol?
Ans: We are using Kerberos V 5.0.

37. What is the authentication protocol in Windows NT?
Ans: Windows NT supported two kinds of challenge/response authentication:
LanManager (LM) challenge/response
Windows NT challenge/response (also known as NTLM challenge/response)

38. What are RAID levels?
Ans: Main RAID levels are RAID-0, RAID-1, RAID-5 and RAID-10.

39. Which RAID you will recommend and why?
Ans: RAID-1 for O.S - mirroring
RAID-5 for DATA partition- Stripe set with parity.

40. What are the different RAID1 and RAID 5?RAID-1:- In RAID-1 two hard disk are there and the data on one is mirrored to another. So even if one fails other one is there with the same data for service continuity.
RAID-5: We can use minimum three hard disk and maximum depend upon RAID controller card, Data written on disk in stripes with distributed parity set.

41. What are the Different between and disk mirroring and disk duplexing?

Ans:

Disk Mirroring: Disk mirroring (also known as RAID-1) is the practice of duplicating data in separate volumes on two hard disks to make storage more fault-tolerant. Mirroring provides data protection in the case of disk failure, because data is constantly updated to both disks. However, since the separate disks rely upon a common controller, access to both copies of data is threatened if the controller fails.

Disk Duplexing: Disk duplexing is a variation of disk mirroring in which each of multiple storage disks has its own SCSI controller. Disk duplexing overcomes this problem; the use of redundant controllers enables continued data access as long as one of the controllers continues to function.
Since the controllers for each disk are different, one of the disks keeps working even if the other disk fails or one of the disk controller fails. So it gives us the luxury to plan for the downtime based on our convinience. Another benefit of disk duplexing is increased throughput. Using a technique known as a split seek, whichever disk can deliver the requested data more quickly responds. Multiple requests may also be split between the disks for simultaneous processing.

42. What is the dynamic disk?Dynamic disks provide the ability to create volumes that span multiple disks (spanned and striped volumes) and the ability to create fault-tolerant volumes (mirrored and RAID-5 volumes).Dynamic disks offer greater flexibility for volume management because they use a database to track information about dynamic volumes on the disk and about other dynamic disks in the computer. Because each dynamic disk in a computer stores a replica of the dynamic disk database, for example, a corrupted dynamic disk database can repair one dynamic disk by using the database on another dynamic disk.

Dynamic disks are a separate form of volume management that allows volumes to have noncontiguous extents on one or more physical disks. Dynamic disks and volumes rely on the Logical Disk Manager (LDM) and Virtual Disk Service (VDS) and their associated features. These features enable you to perform tasks such as converting basic disks into dynamic disks, and creating fault-tolerant volumes. To encourage the use of dynamic disks, multi-partition volume support was removed from basic disks, and is now exclusively supported on dynamic disks.

The following operations can be performed only on dynamic disks:
1) Create and delete simple, spanned, striped, mirrored, and RAID-5 volumes.
2) Extend a simple or spanned volume.
3) Remove a mirror from a mirrored volume or break the mirrored volume into two volumes.
4) Repair mirrored or RAID-5 volumes.
5) Reactivate a missing or offline disk.

43. What is disk striping?
Ans: Disk striping is the technique of spreading data over multiple disks. The data to be stored is divided into blocks and spread across several partitions on various hard disk. Disk striping is used with or without equivalence. Disk striping helps in improving the performance of the disk.

44. What are the backup types?
Ans:
(i) Normal or full Backup
(ii) Deferential Backup
(iii)Incremental Backup
(iv)Copy backup
(v)Daily Backup

45. Which type backup reset archive bits?
Ans: The bit which has check mark on the folder whose backup has been done using normal backup method.

46. What is the use of DFS?
Ans: Distributed File System, It is used for the fault tolerance because it makes the duplicate copy of every DFS root. Not only that the domain login process as well uses DFS to find out the nearest DC to login.

47. Do you know about FRS?
Ans: File Replication Services.
Example: Replication of SYSVOL folder.

48. What are difference between TCP and UDP protocol?
Ans: TCP is a connection orientated protocol while UDP is not a connection orientated protocol.

49. What is different between HUB and Switch?Ans: HUB broadcast the data packet but Switches multicast the data packet into the network which reduces the collision of data packets.

50. Which layer of OSI model does the Router works in?
Ans: One layer Three (Network layer)

51. You are going to migrate the domain how to plan?
Ans: The answer is here.

52. For project requirement you going to share 20 folders what is the step you will take?
53. What is the need of a VLAN?Ans: To divide/restrict the traffic into one segment of the network.

54. What kind of privilege is required to transfer FSMO roles?
Ans. logged-on user should be a member of the Enterprise Administrators group to transfer Schema master or Domain naming master roles, or a member of the Domain Administrators group of the domain where the PDC emulator, RID master and the Infrastructure master roles are being transferred.

55. Write down the command line to transfer all the FSMO roles to other server?
Ans: Click Start, click Run, type ntdsutil in the Open box, and then click OK
Type roles, and then press ENTER.
Type connections, and then press ENTER.
Type connect to server servername, and then press ENTER, where servername is the name of the domain controller that you want to assign the FSMO role to.
At the server connections prompt, type q, and then press ENTER.
Type transfer role, where role is the role that you want to transfer. For example,
To transfer the RID master role, type transfer schema master
To transfer the RID master role, type transfer domain naming master
To transfer the RID master role, type transfer rid master
To transfer the RID master role, type transfer pdc
To transfer the RID master role, type transfer infrastructure master
7. At the fsmo maintenance prompt, type q, and then press ENTER to gain access to the ntdsutil prompt.

56. Write down the command line to seize all the FSMO roles to a server?Ans:
Click Start, click Run, type ntdsutil in the Open box, and then click OK
Type roles, and then press ENTER.
Type connections, and then press ENTER.
Type connect to server servername, and then press ENTER, where servername is the name of the domain controller that you want to assign the FSMO role to.
At the server connections prompt, type q, and then press ENTER.
Type seize role, where role is the role that you want to seize. For example,
To seize the RID master role, type seize schema master
To seize the RID master role, type seize domain naming master
To seize the RID master role, type seize rid master
To seize the RID master role, type seize pdc
To seize the RID master role, type seize infrastructure master.
7. At the fsmo maintenance prompt, type q, and then press ENTER to gain access to the ntdsutil prompt.

57. Command for removing active directory?
Ans: dcpromo /forceremoval

58. How to test whether a domain controller is also a global catalog server:

Click Start, point to Programs, point to Administrative Tools, and then click Active Directory Sites and Services.

Double-click Sites in the left pane, and then locate the appropriate site or click Default-first-site-name if no other sites are available.

Open the Servers folder, and then click the domain controller.

In the domain controller's folder, double-click NTDS Settings.

On the Action menu, click Properties.

On the General tab, view the Global Catalog check box to see if it is selected.

Active Directory Interview Question & Answer

2015-03-03T17:33:00.001+05:30

1. What is Active Directory schema?
Answer: The schema is the Active Directory component that defines all the objects and attributes that the directory service uses to store data.

2. What is global catalog server?
Answer: The global catalog is the set of all objects in an Active Directory Domain Services (AD DS) forest. A global catalog server is a domain controller that stores a full copy of all objects in the directory for its host domain and a partial, read-only copy of all objects for all other domains in the forest.

3. Which is the default protocol used in directory services?
Answer: Lightweight Directory Access Protocol (LDAP)

4. What is IPv6?
Answer: IPv6 is short for "Internet Protocol Version 6". IPv6 is the Internet's next-generation protocol, designed to replace the current Internet Protocol, IP Version 4. IPv4 allows to connect 4.3 billion IP address, where as IPv6 allows 340 trillion IP addresses to be used.

5. What is the default domain functional level in Windows Server 2003?
Answer: Mixed mode functional level

6. What are the physical & logical components of ADS?
Answer: The physical component of Active directory contain all the physical subnet present in your network like domain controllers and replication between domain controllers.
The logical structures of active directory include forest, domains, tree, OUs and global catalogs.

7. What is multimaster replication?
Answer: Multi-master replication is a method of database replication which allows data to be stored by a group of computers, and updated by any member of the group

8. What is a site?
Answer: Sites in Active Directory® represent the physical structure, or topology, of your network. Active Directory uses topology information, stored as site and site link objects in the directory, to build the most efficient replication topology. You use Active Directory Sites and Services to define sites and site links. A site is a set of well-connected subnets. Sites differ from domains; sites represent the physical structure of your network, while domains represent the logical structure of your organization.

9. Which is the command used to remove active directory from a domain controller?
Answer: Dcpromo /forceremoval

10. What is trust?
Answer: To allow users in one domain to access resources in another, Active Directory uses trusts.
Trusts inside a forest are automatically created when domains are created. The forest sets the default boundaries of trust, and implicit, transitive trust is automatic for all domains within a forest.

11. What is the file that’s responsible for keep all Active Directory database?
ANSWER: 1. ntds.dit : This is the main database file for active directory.

2. edb.log : When a transaction performed to ad database, like writing some data first the data will be stored to this file. And after that it will be sent to database. So the system performance will be depends on how this data from edb.log file will be written to ntds.dit
3. res1.log : Used as reserve space in the case when drive had low space. It is basically 10MB in size and creted when we run dcpromo.
4. res2.log : Same as res1.log. It is also 10MB in size and the purspose also same.
5. edb.chk : This file records the transactions committed to ad database. During shutdown, shutdown statement is written to this file. If it is not found when the system rebooted, the ad database tries to check with edb.log for the updated information.

12. What is the SYSVOL folder?
Answer: All active directory data base security related information store in SYSVOL folder and its only created on NTFS partition.

13. What are application partitions? When do I use them?
Answer: Application directory partitions: These are specific to Windows Server 2003 domains.
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.

14. What is the Global Catalog?
The global catalog contains a complete replica of all objects in Active Directory for its Host domain, and contains a partial replica of all objects in Active Directory for every other domain in the forest.

15. Feature of AD?
Answer: Fully Integrated Security, integration with DNS, Policy Based Administration, Scalable, Flexible, Extensible, inter operability with other directory services.

16. What is structure of AD?
Logical & Physical

17. What is the Component of AD?
Logical Structure: Domains, Tress, Forests and OU.
Physical Structure: Sites and Domain Controllers.

18. What is a Domain?
Domain is collection of computers connected together with a server and users.

19. What is a Tree?
Tree is a logical component of AD, is a collection of domains which share contiguous.

20. What is a Forest?
Collection of trees which contain domains

21. What is a child DC?
CDC is a sub domain controller under root domain controller which share name space.

22. What is a roll of ADC?
It maintains backup of AD to provide fault tolerance and network load balancing.

23. What are the tools found after installing a DC?
Active Directory User and Computers,
Active Directory Sites and Services,
Active Directory Domain & Trust,
Domain Controller Security Policy,
Domain Security Policy

24. What is the diff. functional level of 2003?
Domain functional level & Forest functional level

25. What is a standalone server?
Server which is not a part of domain

26. What is a Schema?
Schema is design of AD, defines objects and classes, set of rules.

27. What is an FSMO?
Flexible Single Master Operation

28. What is the diff. operation master of 2003?
Schema Master, Domain Naming Master, PDC Emulator, Infrastructure Master, RID Masters.

29. What is a Schema Master?
Is responsible for overall management, structure and design of schema Only one schema master in entire forest

30. What is domain naming master?
Is responsible for addition or removal of domains and maintaining unique domain names only one domain naming master in entire forest

31. What is a PDC Emulator?
Is responsible for providing backup compatibility for NT BDCs, in mixed mode it acts like a PDC for BDCs. It updates the password changes, synchronizes time between DCs. Only one PDC Emulator per domain.

32. What is infrastructure Master?
Is responsible for updating user and group information and updating Global Catalog Only one infrastructure master per domain

33. What is RID Master?
Relative identifier is responsible for assigning unique IDs to the object s created in the AD. Only one RID Master per domain.

DESKTOP LEVEL INTERVIEW QUESTION & ANSWER

2015-03-03T17:15:00.001+05:30

PORT NUMBERS

15 è Netstat

21 è FTP

23 è Telnet

25 è SMTP

37 @ TIME

42 è WINS

53 è DNS

67 è Bootp

68 è DHCP

79 @ FINGER

80 è HTTP

88 è Kerberos

101 è HOSTNAME

115 @ SFTP

110 è POP3

119 è NNTP

123 è NTP (Network time protocol)

139 è NetBIOS

161 è SNMP

180 è RIS

220 @ IMAP3

389 è LDAP (Lightweight Directory Access Protocol)

443 è HTTPS (HTTP over SSL/TLS)

443 è SSL (https) (http protocol over TLS/SSL

500 @ INTERNET KEY EXCHANGE

520 è RIP

3269 @ AD GLOBAL CATALOG

3389 è Terminal services

9100 @ GOOGLE

1) Components of computer?

Ans: Two types of components. Processing devices are the components responsible for the processing of information within the computer system. These include devices such as the CPU, memory and motherboard. Storage devices are components which allow data to be stored within a computer system such as hard disks.

2) What is SMPS?

Ans: Switch-mode power supply.

3) What is BIOS?

Ans: Basic input/output system. It is the program a computer's microprocessor uses to get the computer system started after it is turned on. It also manages data flow between the computer's operating system and attached devices such as the hard disk, video adapter, keyboard, mouse and printer.

4) What is POST?

Ans: Power-on self-test. A power-on self-test (POST) is a process performed by firmware or software routines immediately after a computer or other digital electronic device is powered on.

5) What is the boot process of XP?

Ans:

6) What is DHCP? Port number?

Ans: Dynamic Host Configuration Protocol. It automatically assigns IP to the system in the network , it has a process called DORA , D- Discover ,O-Offer , R- Request , A- Acknowledge. Port number 67 for Server and 68 for Client.

7) What is DNS? Port Number?

Ans: Domain naming system it resolves IP to Host name and host name to IP address. Port number is 53.

8) What is AD?

Ans: Active directory. Active Directory is a database that keeps track of all the user accounts and passwords in an organization. It allows to store user accounts and passwords in one protected location, improving organization's security. Active Directory is subdivided into one or more domains.

9) What is SMTP? Port number?

Ans: Simple Mail Transfer Protocol. It helps in sending mails. Port number is 25.

10) What is POP3?

Ans: Post Office Protocol version 3. It is a standard mail protocol used to receive emails from a remote server to a local email client. POP3 allows you to download email messages on your local computer and read them even when you are offline.

11) What is IP Address?

Ans: Internet Protocol. This is used to communicate to other systems over the network.

12) What is Subnet mask?

Ans: It is called a subnet mask because it is used to identify network address of an IP address by performing a bitwise AND operation on the netmask. A Subnet mask is a 32-bit number that masks an IP address, and divides the IP address into network address and host address.

13) How many classes of IP addresses are there and the ranges?

Ans: There are 5 types of classes , Class A – 0 to 126, Class B – 128 to 191 , Class C 192 to 223, Class D – 224 to 239, Class E – 240 to 254.

14) What is Hub, Switch and Router?

Ans:

15) What is OSI layer?

Ans: The Open Systems Interconnection is a conceptual model that characterizes and standardizes the internal functions of a communication system by partitioning it into abstraction layers. The model groups communication functions into 7 logical layers. 1: physical layer; 2: data link layer; 3: network layer; 4: transport layer; 5: session layer; 6: presentation layer; 7: application layer.

16) What is Static IP and Dynamic IP?

Ans: Static IP addresses are reserved IP addresses and do not change over time while dynamic IP addresses can change each time when connecting to the Internet.

17) How will you know if the IP assigned is Static or Dynamic?

Ans: The simple way is to check the IP address each time we connect to internet or we can use ipconfig/all in the command prompt or we can check the status option of the internet connection in the control panel.

18) How will you enable remote desktop on the computer?

Ans: Click start button, right click computer, click properties and select "allow Remote Assistance to this computer."

19) Difference between Remote Desktop and Remote assistance?

Ans: Remote Desktop is to access one computer from another remotely. Remote Assistance is to give or receive assistance remotely.

20) How will you join system to domain?

Ans: To connect a system to a domain, you'll need to know the name of the domain and have a valid user account on the domain. Click start, click computer and properties. Under 'computer name' tab, click 'change.' Under 'member of,' select domain and give the name of the domain. Type in the username and password given to connect to the domain.

21) What will you do when a system is affected from Virus?

Ans: Check whether an antivirus program is installed, and if yes, update it and scan the entire system. If there is no antivirus installed, scan the system with an online antivirus program, scan the system thoroughly and disinfect the virus.

22) What is SCCM?

Ans: System Center Configuration Manager. SCCM is a software management suite provided by Microsoft that allows users to manage a large number of Windows based computers. SCCM features remote control, patch management, operating system deployment, network protection and other various services.

23) What is SCOM?

Ans: System Center Operations Manager. SCOM is a data center management system designed for Windows Server and Unix-based operating systems. SCOM provides a user interface for viewing a system's functionality, state and performance. Alerts can also be configured for availability, configuration, performance and security events.

24) What is blue dump error and how will you fix it?

Ans: System crashes usually because of bad memory module (RAM Configuration), failing hard drive, virus/Trojan attack etc., and there is no single fix for that. To Fix Blue Screen Memory Dump Error, try the following: 1. Repair/Clean Registry. 2. Scan for Virus. 3. Check the recently installed hardware and device driver. 4. Check for a faulty RAM or ports.

25) What will u do when u see NTLDR missing?

Ans: Disconnect any non-bootable external devices, check the BIOS settings and ensure they are correct, restore ntdlr and ntdetect.com, perform repair installation or perform a clean installation.

26) Difference between FAT32 and NTFS?

Ans: FAT32 (File Allocation Table 32-bit) file systems used in Windows ME and lower. NTFS (New Technology File System) is used in Windows 2000 and newer. FAT32 only supports files no larger than 3.9 GB and NTFS supports files larger than 4 GB in size. NTFS is more secure and advanced compared to FAT32.

1.Difference between Switch and Hub

Switch HUB

a. Works at layer 2 works at layer 1
b. Uses MAC address for packet uses broadcast for packet forwarding
forwarding
c. Does not required CSMA/CD requires CSMA/CD
d. Faster than HUB Slower than Switch
e. Full-duplex Half-duplex
f. high throughput Low throughput

2.What is bandwidth of of CAT5 & CAT 6 cables?

Answer: CAT 5 - 100 Mbps, CAT 6 – 1000 Mbps

3. What is the recommended CAT5 cable length between switch and PC ?

Answer: 100 meters

4. When to use cross cable and straight cable?

Answer: Similar device = cross cable

• Switch to switch

• PC to PC

• Hub to HUB

• Switch to HUB

• PC to router

• router to router

Unsimilar device = straight cable

• PC to switch

• PC to HUB

• Router to Switch

5. Difference between domain and work group?

Answer:

Domain Workgroup

A. centralized network model Decentralized network

B. Domain is controlled by DC No centralized control

C. Centralized login Local login

D. centralized user database local user data based

E. Easy and centralized management NA

F. good for large network good for small network

6. Explain in short about all 7 layers of OSI

Answer:

• Application layer - user interface and application Data conversion

• Presentation layer - and transformation keep data of diff

• Session layer - application separately end to end connectivity

• Transport layer - using port numbers, logical addressing like IP

• Network layer - address. Physical addressing like MAC

• Data link layer - address. Physical transmission of data using

• Physical layer - O's and l's.

7. What if forest. ?

Answer: forest is collection of single or multiple trees.

8. What is trees?

Answer: Trees are collection of single or multiple domain arrange in hierarchy using child-parent relationship.

9. Which authentication protocols are supported by ADS?

Answer: NTLM and Kerberos

10. What is Global Catalog?

Answer: GC is a DC which maintains full copy of local domain parti on and partial copy of entire forest.

11.Define Active directory service?

Answer: ADS is a new logical network model of windows 2000 and 2003 which includes forest, trees, domain, etc.

12.What is function of LDAP?

Answer: LDAP is a protocol used to query or access active directory database. It uses port 389.

13. What are the requirements for ADS?

Answer:

A) Windows 2000/2003 Server Operating System

b) TCP/IP protocol and IP address

c) Network Card with Active state

d) NTFS partition

14. What is Sysvol?

Answer: Sysvol (System Volume) a special folder located on NTFS partition of DC for storing domain public files like logon script, GPO templates, etc. The contents of sysvol folder are replicated to all DC in a domain.

15. Difference between FAT32 and NTFS?

Answer:

FAT32 NTFS

a. Supported by win9x, 2000, 2003, xp Supported by NT, 2000, 2003, xp

b. Remote security Local security

c. NA compression and encryption

d. NA Hot Fixing

e. NA Shadow copy and Disk quota

16. Difference between Basic disk and dynamic disk?

Answer:

Basic Disk Dynamic disk

partition are created Volumes are created

can be converted to dynamic cannot be converted to basic

grouping of disk not allowed grouping of disk are allowed

No data redundancy data redundancy using RAID 1/5

partition table is at start Partition table is at end

17. Explain about RAID-1

Answer:

A. Min. and max. 2 hard disk

b. If any one disk fails data can be recovered from other disk.

c. 50% space wastage.

D. no read/write performance improvement.

E. good for storing Operating system.

18. Explain about RAID-5

Answer:

A. data is stored in distributed format across all the disk

B. min 3 max. 32

C. if any one disk fails data can be recovered using parity.

D. parity space wastage eg. parity = total space \ no of disk.

E. good for storing data.

19. Can we convert FAT32 to NTFS? How?

Answer: you can convert FAT32 partition to NTFS using convert.exe command.

Eg . convert /fs:ntfs

20. What is mounting?

Answer: mounting is a process of assigning or mapping of the folder to a drive.

21. What is RAID?

Answer: RAID is a technology of grouping disk in order to provide more space and redundancy. There are total 54 RAID method. Windows 2003 support RAID 0, 1 and 5.

22. What is difference between mirroring and duplexing?

Answer: Mirroring requires single controller and duplexing requires two controllers.

23. What is Web Server?

Answer: Web server is a server or application server which host or stores websites. Every web site should have a name like www.vision.com and IP address. Eg. IIS, Apache server, etc.

34. What is mail server?

Answer: Mail server is a software which maintains user mailboxes, eg : Exchange server , Lotus domino, etc.

35. What is mail client?

Answer: software used by client to access to mails stores on mail server, using mail client software you can send mail and receive mail. Eg: Microsoft Outlook, Outlook Express, Lotus notes, etc.

36. What is Proxy server?

Answer: It is software used for sharing of internet connection.

E.g. Wingate, Win proxy, Analog proxy, etc.

37. Port numbers for various application and services?

Answer:

There are total 65536 ports available. Below are the lists of some well-known ports.

LDAP : 389

Global catalog:

Kerberos : 88

DNS : 53

SMTP : 25

POP3 : 110

Telnet : 23

NNTP : 119

IMAP : 143

RPC : 135

HTTP : 80

HTTPS/SSL : 443

FTP : 21

38. What is firewall?

Answer: It is software used to provide security to your network by not allowing unauthorized access to your internal network from External users. Eg: PIX firewall, Checkpoint firewall, etc.

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.

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.

9) What is a DOMAIN? What is the difference between a domain and a workgroup?
Domain is created when we install Active Directory. ITs 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 commo 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. Install the OS with the latets patches, 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

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 called manageable switches. For example we can create VLAN for on such switch. On no manageable switches we can't do so.

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.

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.

Installation & Configuration of Postfix in RHEL AS 4.0

2015-03-03T14:45:00.001+05:30

Go to Terminal

Start the postfix service

#chkconfig postfix on
#service postfix start

Now open the postfix main configuration file

#vi /etc/postfix/main.cf

UN comments the myhostname, mydomain and Change the hostname, mydomain

Myhostname = web7.webserver.com

Mydomain = webserver.com

Windows 2008 Server Interview Questions Part II

2015-03-02T21:54:00.000+05:30

1. What are the Important Windows port numbers:

RDP – 3389 – (windows rdp port number and remote desktop port number)
FTP – 21 – (file transfer protocol)
TFTP – 69 – ( tftp port number )
Telnet – 23 – ( telnet port number)
SMTP – 25 – ( SMTP port number)
DNS – 53 – ( dns port number and Domain Name System port number)
DHCP – 68 – (DHCP port number and Dynamic Host Configuration Protocol port number )
POP3 – 110 – ( post office Protocol 3 port )
HTTP – 80 – (http port number)
HTTPS – 443 – (https port number)
NNTP – 119 – ( Network News Transfer Protocol Port number )
NTP – 123 – (ntp port number and network Time Protocol and SNTP port number )
IMAP – 143 – (Internet Message Access Protocol port number)
SSMTP – 465 – ( SMTP Over SSl )
SIMAP – 993 – ( IMAP Over SSL )
SPOP3 – 995 – ( POP# Over SS L)
Time – 123 – ( ntp port number and network Time Protocol and SNTP port number )
NetBios – 137 – ( Name Service )
NetBios – 139 – ( Datagram Service )
DHCP Client – 546 – (DHCP Client port number)
DHCP Server – 547 – (DHCP Server port number)
Global Catalog – 3268 – (Global Catalog port number)
LDAP – 389 – ( LDAP port number and Lightweight Directory Access Protocol port number )
RPC – 135 – (remote procedure call Port number)
Kerberos – 88 – ( Kerberos Port Number)
SSH – 22 – ( ssh port number and Secure Shell port number)

2. How to check tombstone lifetime value in your Forest

Tombstone lifetime value different from OS to OS, for windows server 2000/2003 it’s 60 days, In Windows Server 2003 SP1, default tombstone lifetime (TSL) value has increased from 60 days to 180 days, again in Windows Server 2003 R2 TSL value has been decreased to 60 days, Windows Server 2003 R2 SP2 and windows server 2008 it’s 180 days

If you migrating windows 2003 environment to windows 2008 then its 60 day’s

you can use the below command to check/view the current tombstone lifetime value for your Domain/Forest

dsquery * “cn=directory service,cn=windows nt,cn=services,cn=configuration,dc=” –scope base –attr tombstonelifetime

Replace forestDN with your domain partition DN, for domainname.com the DN would be dc=domainname, dc=com

Source: http://technet.microsoft.com/en-us/library/cc784932(WS.10).aspx

3. How to find the domain controller that contains the lingering object

If we enable Strict Replication Consistency

Lingering objects are not present on domain controllers that log Event ID 1988. The source domain controller contains the lingering object

If we doesn’t enable Strict Replication Consistency

Lingering objects are not present on domain controllers that log Event ID 1388. Domain controller that doesn’t log Event ID 1388 and that domain controller contain the lingering object

You have a 100 Domain controllers which doesn’t enable Strict Replication Consistency, then you will get the Event ID 1388 on all the 99 Domain controllers except the one that contain the lingering object

Need to Remove Lingering Objects from the affected domain controller or decommission the domain controller

You can use Event Comb tool (Eventcombmt.exe) is a multi-threaded tool that can be used to gather specific events from the Event Viewer logs of different computers at the same time.

You can download these tools from the following location:

http://www.microsoft.com/downloads/details.aspx?FamilyID=9d467a69-57ff-4ae7-96ee-b18c4790cffd&DisplayLang=en

4. What are Active Directory ports:

List of Active Directory Ports for Active Directory replication and Active Directory authentication, this ports can be used to configure the Firewall

Active Directory replication- There is no defined port for Active Directory replication, Active Directory replication remote procedure calls (RPC) occur dynamically over an available port through RPCSS (RPC Endpoint Mapper) by using port 135

File Replication Services (FRS)- There is no defined port for FRS, FRS replication over remote procedure calls (RPCs) occurs dynamically over an available port by using RPCSS (RPC Endpoint Mapper ) on port 135

Other required ports for Active Directory
TCP 53 – DSN (DNS Download)
UDP 53 – DSN (DNS Queries)
TCP 42- WINS
UDP 42- WINS
TCP 3389- RDP (Remote Desktop)
TCP 135 – MS-RPC
TCP 1025 & 1026 – AD Login & replication
TCP 389 – LDAP
TCP 639 – LDAP over SSL/TLS
TCP 3268 -Global Catalog
TCP 3268 – Global Catalog over SSL/TSL
UDP 137 & 138 – NetBIOS related
UDP 88 – Kerberos v5
TCP 445 – SMB , Microsoft-ds
TCP 139 – SMB

5. How to do active directory health checks?

As an administrator you have to check your active directory health daily to reduce the active directory related issues, if you are not monitoring the health of your active directory what will happen

Let’s say one of the Domain Controller failed to replicate, first day you will not have any issue. If this will continue then you will have login issue and you will not find the object change and new object, that’s created and changed in other Domain Controller this will lead to other issues

If the Domain Controller is not replicated more then 60 day’s then it will lead to Lingering issue

Command to check the replication to all the DC’s(through this we can check Active Directory Health)

Repadmin /replsum /bysrc /bydest /sort:delta

You can also save the command output to text file, by using the below command

Repadmin /replsum /bysrc /bydest /sort:delta >>c:\replication_report.txt

this will list the domain controllers that are failing to replicate with the delta value
You can daily run this to check your active directory health

6. GPRESULT falied with access denied error:

Unable to get the result from gpresult on windows 2003 server, gpresult return with the access denied errors, you can able to update the group policy without issue

Run the following commands to register the userenv.dll and recompile the rsop mof file
To resolve the access denied error while doing the gpresult.
1. Open a cmd
1. re-register the userenv.dll
Regsvr32 /n /I c:\winnt\system32\userenv.dll
2. CD c:\windows\system32\wbem
3. Mofcomp scersop.mof
4. Gpupdate /force
5. Gpresult

Now you able to run the gpresult without error and even server reboot not required for this procedure

7. What is the command to find out site name for given DC

dsquery server NYDC01 -site

domain controller name = NYDC01

8. Command to find all DCs in the given site

Command to find all the Domain Controllers in the “Default-First-Site-Name” site

dsquery server -o rdn -site Default-First-Site-Name

Site name = Default-First-Site-Name

9. How many types of queries DNS does?

Iterative Query
Recursive Query

Iterative Query

In this query the client ask the name server for the best possible answer, the name server check the cache and zone for which it’s authoritative and returns the best possible answer to the client, which would be the full answer like IP address or try the other name server

Recursive Query

Client demands either a full answer or an error message (like record or domain name does not exist)
Client machine always send recursive query to the DNS server, if the DNS server does not have the requested information, DNS server send the iterative query to the other name server (through forwarders or secondary DNS server) until it gets the information, or until the name query fails.

Windows Sever 2008/R2 Interview questions Part 1

2015-03-02T21:52:00.001+05:30

Difference between 2003 and 2008

1) 2008 is combination of vista and windows 2003r2. Some new services are introduced in it
1. RODC one new domain controller introduced in it [Read-only Domain controllers.]
2. WDS (windows deployment services) instead of RIS in 2003 server
3. shadow copy for each and every folders
4.boot sequence is changed
5.installation is 32 bit where as 2003 it is 16 as well as 32 bit, that’s why installation of 2008 is faster
6.services are known as role in it
7. Group policy editor is a separate option in ads

2) The main difference between 2003 and 2008 is Virtualization, management.
2008 has more inbuilt components and updated third party drivers Microsoft introduces new feature with 2k8 that is Hyper-V Windows Server 2008 introduces Hyper-V (V for Virtualization) but only on 64bit versions. More and more companies are seeing this as a way of reducing hardware costs by running several ‘virtual’ servers on one physical machine. If you like this exciting technology, make sure that you buy an edition of Windows Server 2008 that includes Hyper-V, then launch the Server Manger, add Roles.

Windows server 2008 new features

1. Virtualization with Hyper V

2. Server Core – provides the minimum installation required to carry out a specific server role, such as for a DHCP, DNS or print server. From a security standpoint, this is attractive. Fewer applications and services on the sever make for a smaller attack surface. In theory, there should also be less maintenance and management with fewer patches to install, and the whole server could take up as little as 3Gb of disk space according to Microsoft

3. IIS 7

4. Role based installation – rather than configuring a full server install for a particular role by uninstalling unnecessary components (and installing needed extras), you simply specify the role the server is to play, and Windows will install what’s necessary — nothing more.

5. Read Only Domain Controllers (RODC)
It’s hardly news that branch offices often lack skilled IT staff to administer their servers, but they also face another, less talked about problem. While corporate data centers are often physically secured, servers at branch offices rarely have the same physical security protecting them. This makes them a convenient launch pad for attacks back to the main corporate servers. RODC provides a way to make an Active Directory database read-only. Thus, any mischief carried out at the branch office cannot propagate its way back to poison the Active Directory system as a whole. It also reduces traffic on WAN links.

6. Enhanced terminal services
Terminal services has been beefed up in Server 2008 in a number of ways. TS RemoteApp enables remote users to access a centralized application (rather than an entire desktop) that appears to be running on the local computer’s hard drive. These apps can be accessed via a Web portal or directly by double-clicking on a correctly configured icon on the local machine. TS Gateway secures sessions, which are then tunnelled over https, so users don’t need to use a VPN to use RemoteApps securely over the Internet. Local printing has also been made significantly easier.

7. Network Access Protection
Microsoft’s system for ensuring that clients connecting to Server 2008 are patched, running a firewall and in compliance with corporate security policies — and that those that are not can be remediated — is useful. However, similar functionality has been and remains available from third parties.

8. Windows PowerShell

Microsoft’s new (ish) command line shell and scripting language has proved popular with some server administrators, especially those used to working in Linux environments. Included in Server 2008, PowerShell can make some jobs quicker and easier to perform than going through the GUI. Although it might seem like a step backward in terms of user friendly operation, it’s one of those features that once you’ve gotten used to it; you’ll never want to give up.

Restartable Active Directory Domain Services: You can now perform many actions, such as offline defragmentation of the database, simply by stopping Active Directory. This reduces the number of instances in which you must restart the server in Directory Services Restore Mode and thereby reduces the length of time the domain controller is unavailable to serve requests from

Enhancements to Group Policy: Microsoft has added many new policy settings. In particular, these settings enhance the management of Windows Vista client computers. All policy management is now handled by means of the Group Policy Management Console (GPMC), which was an optional feature first added to Windows Server 2003 R2. In addition, Microsoft has added new auditing capabilities to Group Policy and added a searchable database for locating policy settings from within GPMC. In Windows Server 2008 R2, GPMC enables you to use a series of PowerShell cmdlets to automate many of the tasks (such as maintenance and linking of GPOs) that you would otherwise perform in the GUI. In addition, R2 adds new policy settings that enhance the management of Windows 7 computers.

Windows Server 2008 R2 new features:

Active Directory Recycle Bin

Windows PowerShell 2.0

Active Directory Administrative Center (ADAC)

Offline domain join

Active Directory health check

Active Directory Web Services

Active Directory Management Pack

Windows Server Migration Tools

Managed Service Accounts

What is server core? How do you configure and manage a windows server 2008 core installation?

The Server Core installation option is an option that you can use for installing Windows Server 2008 or Windows Server 2008 R2. A Server Core installation provides a minimal environment for running specific server roles, which reduces the maintenance and management requirements and the attack surface for those server roles. A server running a Server Core installation of Windows Server 2008 supports the following server roles:

Active Directory Domain Services (AD DS)
Active Directory Lightweight Directory Services (AD LDS)
DHCP Server
DNS Server
File Services
Hyper-V
Print Services
Streaming Media Services
Web Server (IIS)

A server running a Server Core installation of Windows Server 2008 R2 supports the following server roles:

Active Directory Certificate Services
Active Directory Domain Services
Active Directory Lightweight Directory Services (AD LDS)
DHCP Server
DNS Server
File Services (including File Server Resource Manager)
Hyper-V
Print and Document Services
Streaming Media Services
Web Server (including a subset of ASP.NET)

A Server Core installation does not include the traditional full graphical user interface. Once you have configured the server, you can manage it locally at a command prompt or remotely using a Terminal Server connection. You can also manage the server remotely using the Microsoft Management Console (MMC) or command-line tools that support remote use.

Benefits of a Server Core installation

The Server Core installation option of Windows Server 2008 or Windows Server 2008 R2 provides the following benefits:

Reduced maintenance. Because the Server Core installation option installs only what is required to have a manageable server for the supported roles, less maintenance is required than on a full installation of Windows Server 2008.
Reduced attack surface. Because Server Core installations are minimal, there are fewer applications running on the server, which decreases the attack surface.
Reduced management. Because fewer applications and services are installed on a server running the Server Core installation, there is less to manage.
Less disk space required. A Server Core installation requires only about 3.5 gigabytes (GB) of disk space to install and approximately 3 GB for operations after the installation.

How do you promote a Server Core to DC?

In order to install Active Directory DS on your server core machine you will need to perform the following tasks:

1. Configure an unattend text file, containing the instructions for the DCPROMO process. In this example you will create an additional DC for a domain called petrilab.local:

2. Configure the right server core settings

After that you need to make sure the core machine is properly configured.

Perform any configuration setting that you require (tasks such as changing computer name, changing and configure IP address, subnet mask, default gateway, DNS address, firewall settings, configuring remote desktop and so on).

After changing the required server configuration, make sure that for the task of creating it as a DC – you have the following requirements in place:

A partition formatted with NTFS (you should, it’s a server…)
A network interface card, configure properly with the right driver
A network cable plugged in
The right IP address, subnet mask, default gateway

And most importantly, do not forget:

The right DNS setting, in most cases, pointing to an existing internal DNS in your corporate network

3. Copy the unattend file to the server core machine

Now you need to copy the unattend file from wherever you’ve stored it. You can run it from a network location but I prefer to have it locally on the core machine. You can use the NET USE command on server core to map to a network path and copy the file to the local drive. You can also use a regular server/workstation to graphically access the core’s C$ drive (for example) and copy the file to that location.

4. Run the DCPROMO process

Next you need to manually run DCPROMO. To run the Active Directory Domain Services Installation Wizard in unattended mode, use the following command at a command prompt:

Dcpromo /unattend

Reboot the machine

In order to reboot the server core machine type the following text in the command prompt and press Enter.

shutdown /r /t 0

What are RODCs? What are advantages?

A read-only domain controller (RODC) is a new type of domain controller in the Windows Server® 2008 operating system. With an RODC, organizations can easily deploy a domain controller in locations where physical security cannot be guaranteed. An RODC hosts read-only partitions of the Active Directory Domain Services (AD DS) database.

Before the release of Windows Server 2008, if users had to authenticate with a domain controller over a wide area network (WAN), there was no real alternative. In many cases, this was not an efficient solution. Branch offices often cannot provide the adequate physical security that is required for a writable domain controller. Furthermore, branch offices often have poor network bandwidth when they are connected to a hub site. This can increase the amount of time that is required to log on. It can also hamper access to network resources.

Beginning with Windows Server 2008, an organization can deploy an RODC to address these problems. As a result, users in this situation can receive the following benefits:

Improved security
Faster logon times
More efficient access to resources on the network

What does an RODC do?

Inadequate physical security is the most common reason to consider deploying an RODC. An RODC provides a way to deploy a domain controller more securely in locations that require fast and reliable authentication services but cannot ensure physical security for a writable domain controller.

However, your organization may also choose to deploy an RODC for special administrative requirements. For example, a line-of-business (LOB) application may run successfully only if it is installed on a domain controller. Or, the domain controller might be the only server in the branch office, and it may have to host server applications.

In such cases, the LOB application owner must often log on to the domain controller interactively or use Terminal Services to configure and manage the application. This situation creates a security risk that may be unacceptable on a writable domain controller.

An RODC provides a more secure mechanism for deploying a domain controller in this scenario. You can grant a non administrative domain user the right to log on to an RODC while minimizing the security risk to the Active Directory forest.

You might also deploy an RODC in other scenarios where local storage of all domain user passwords is a primary threat, for example, in an extranet or application-facing role.

How do you install an RODC?

1 Make sure you are a member of Domain Admin group

2. Ensure that the forest functional level is Windows Server 2003 or higher

3. Run adprep /rodcprep

3. Install a writable domain controller that runs Windows Server 2008 – An RODC must replicate domain updates from a writable domain controller that runs Windows Server 2008. Before you install an RODC, be sure to install a writable domain controller that runs Windows Server 2008 in the same domain. The domain controller can run either a full installation or a Server Core installation of Windows Server 2008. In Windows Server 2008, the writable domain controller does not have to hold the primary domain controller (PDC) emulator operations master role.

4. You can install an RODC on either a full installation of Windows Server 2008 or on a Server Core installation of Windows Server 2008. Follow the below steps:

Click Start, type dcpromo, and then press ENTER to start the Active Directory Domain Services Installation Wizard.
On the Choose a Deployment Configuration page, click Existing forest, click Add a domain controller to an existing domain
On the Network Credentials page, type the name of a domain in the forest where you plan to install the RODC. If necessary, also type a user name and password for a member of the Domain Admins group, and then clickNext.
Select the domain for the RODC, and then click Next.
Click the Active Directory site for the RODC and click next
Select the Read-only domain controller check box, as shown in the following illustration. By default, the DNS server check box is also selected. To run the DNS server on the RODC, another domain controller running Windows Server 2008 must be running in the domain and hosting the DNS domain zone. An Active Directory–integrated zone on an RODC is always a read-only copy of the zone file. Updates are sent to a DNS server in a hub site instead of being made locally on the RODC.
To use the default folders that are specified for the Active Directory database, the log files, and SYSVOL, clickNext.
Type and then confirm a Directory Services Restore Mode password, and then click Next.
Confirm the information that appears on the Summary page, and then click Next to start the AD DS installation. You can select the Reboot on completion check box to make the rest of the installation complete automatically.

What is the minimum requirement to install Windows 2008 server?

Talk about all the AD-related roles in Windows Server 2008/R2.

Active Directory Domain Services

Active Directory Domain Services (AD DS), formerly known as Active Directory Directory Services, is the central location for configuration information, authentication requests, and information about all of the objects that are stored within your forest. Using Active Directory, you can efficiently manage users, computers, groups, printers, applications, and other directory-enabled objects from one secure, centralized location.

Benefits

Lower costs of managing Windows networks.
Simplify identity management by providing a single view of all user information.
Boost security with the ability to enable multiple types of security mechanisms within a single network.
Improve compliance by using Active Directory as a primary source for audit data.

Active Directory Rights Management Services

Your organization’s intellectual property needs to be safe and highly secure. Active Directory Rights Management Services, a component of Windows Server 2008, is available to help make sure that only those individuals who need to view a file can do so. AD RMS can protect a file by identifying the rights that a user has to the file. Rights can be configured to allow a user to open, modify, print, forward, or take other actions with the rights-managed information. With AD RMS, you can now safeguard data when it is distributed outside of your network.

Active Directory Federation Services

Active Directory Federation Services is a highly secure, highly extensible, and Internet-scalable identity access solution that allows organizations to authenticate users from partner organizations. Using AD FS in Windows Server 2008, you can simply and very securely grant external users access to your organization’s domain resources. AD FS can also simplify integration between untrusted resources and domain resources within your own organization.

Active Directory Certificate Services

Most organizations use certificates to prove the identity of users or computers, as well as to encrypt data during transmission across unsecured network connections. Active Directory Certificate Services (AD CS) enhances security by binding the identity of a person, device, or service to their own private key. Storing the certificate and private key within Active Directory helps securely protect the identity, and Active Directory becomes the centralized location for retrieving the appropriate information when an application places a request.

Active Directory Lightweight Directory Services

Active Directory Lightweight Directory Service (AD LDS), formerly known as Active Directory Application Mode, can be used to provide directory services for directory-enabled applications. Instead of using your organization’s AD DS database to store the directory-enabled application data, AD LDS can be used to store the data. AD LDS can be used in conjunction with AD DS so that you can have a central location for security accounts (AD DS) and another location to support the application configuration and directory data (AD LDS). Using AD LDS, you can reduce the overhead associated with Active Directory replication, you do not have to extend the Active Directory schema to support the application, and you can partition the directory structure so that the AD LDS service is only deployed to the servers that need to support the directory-enabled application.

What are the new Domain and Forest Functional Levels in Windows Server 2008/R2?

Domain Function Levels

To activate a new domain function level, all DCs in the domain must be running the right operating system. After this requirement is met, the administrator can raise the domain functional level. Here’s a list of the available domain function levels available in Windows Server 2008:

Windows 2000 Native Mode

This is the default function level for new Windows Server 2008 Active Directory domains.

Supported Domain controllers – Windows 2000, Windows Server 2003, Windows Server 2008.

Windows Server 2003 Mode

To activate the new domain features, all domain controllers in the domain must be running Windows Server 2003. After this requirement is met, the administrator can raise the domain functional level to Windows Server 2003.

Supported Domain controllers – Windows Server 2003, Windows Server 2008.

Windows Server 2008 Mode

Supported Domain controllers – Windows Server 2008.

Windows 2008 Forest function levels

Forest functionality activates features across all the domains in your forest. To activate a new forest function level, all the domain in the forest must be running the right operating system and be set to the right domain function level. After this requirement is met, the administrator can raise the forest functional level. Here’s a list of the available forest function levels available in Windows Server 2008:

Windows 2000 forest function level

This is the default setting for new Windows Server 2008 Active Directory forests.

Supported Domain controllers in all domains in the forest – Windows 2000, Windows Server 2003, Windows Server 2008.

Windows Server 2003 forest function level

To activate new forest-wide features, all domain controllers in the forest must be running Windows Server 2003.

Supported Domain controllers in all domains in the forest – Windows Server 2003, Windows Server 2008.

Windows Server 2008 forest function level

To activate new forest-wide features, all domain controllers in the forest must be running Windows Server 2008.

Supported Domain controllers in all domains in the forest – Windows Server 2008.

To activate the new domain features, all domain controllers in the domain must be running Windows Server 2008. After this requirement is met, the administrator can raise the domain functional level to Windows Server 2008.

When a child domain is created in the domain tree, what type of trust relationship exists between the new child domain and the trees root domain?

Transitive and two way.

http://technet.microsoft.com/en-us/library/cc775736%28WS.10%29.aspx

Which Windows Server 2008 tools make it easy to manage and configure a servers roles and features?

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

What is WDS? How is WDS configured and managed on a server running Windows Server 2008?

The Windows Deployment Services is the updated and redesigned version of Remote Installation Services (RIS). Windows Deployment Services enables you to deploy Windows operating systems, particularly Windows Vista. You can use it to set up new computers by using a network-based installation. This means that you do not have to install each operating system directly from a CD or DVD.

Benefits of Windows Deployment Services

Windows Deployment Services provides organizations with the following benefits:

Allows network-based installation of Windows operating systems, which reduces the complexity and cost when compared to manual installations.
Deploys Windows images to computers without operating systems.
Supports mixed environments that include Windows Vista, Microsoft Windows XP and Microsoft Windows Server 2003.
Built on standard Windows Vista setup technologies including Windows PE, .wim files, and image-based setup.

Prerequisites for installing Windows Deployment Services

Your computing environment must meet the following technical requirements to install Windows Deployment Services:

Active Directory. A Windows Deployment Services server must be either a member of an Active Directory domain or a domain controller for an Active Directory domain. The Active Directory domain and forest versions are irrelevant; all domain and forest configurations support Windows Deployment Services.
DHCP. You must have a working Dynamic Host Configuration Protocol (DHCP) server with an active scope on the network because Windows Deployment Services uses PXE, which relies on DHCP for IP addressing.
DNS. You must have a working Dynamic Name Services (DNS) server on the network to run Windows Deployment Services.
An NTFS partition. The server running Windows Deployment Services requires an NTFS file system volume for the image store.
Credentials. To install the role, you must be a member of the Local Administrators group on the Windows Deployment Services server. To install an image, you must be a member of the Domain Users group.
Windows Server 2003 SP1 or SP2 with RIS installed. RIS does not have to be configured, but must be installed.

http://technet.microsoft.com/en-us/library/cc766320%28WS.10%29.aspx#BKMK_1

Name some of the major changes in GPO in Windows Server 2008.

Cost savings through power options

In Windows Server 2008, all power options have been Group Policy enabled, providing a potentially significant cost savings. Controlling power options through Group Policy could save organizations a significant amount of money. You can modify specific power options through individual Group Policy settings or build a custom power plan that is deployable by using Group Policy.

Ability to block device installation

In Windows Server 2008, you can centrally restrict devices from being installed on computers in your organization. You will now be able to create policy settings to control access to devices such as USB drives, CD-RW drives, DVD-RW drives, and other removable media.

Improved security settings

In Windows Server 2008, the firewall and IPsec Group Policy settings are combined to allow you to leverage the advantages of both technologies, while eliminating the need to create and maintain duplicate functionality. Some scenarios supported by these combined firewall and IPsec policy settings are secure server-to-server communications over the Internet, limiting access to domain resources based on trust relationships or health of a computer, and protecting data communication to a specific server to meet regulatory requirements for data privacy and security.

Expanded Internet Explorer settings management

In Windows Server 2008, you can open and edit Internet Explorer Group Policy settings without the risk of inadvertently altering the state of the policy setting based on the configuration of the administrative workstation. This change replaces earlier behavior in which some Internet Explorer policy settings would change based on the policy settings enabled on the administrative workstation used to view the settings

Printer assignment based on location

The ability to assign printers based on location in the organization or a geographic location is a new feature in Windows Server 2008. In Windows Server 2008, you can assign printers based on site location. When mobile users move to a different location, Group Policy can update their printers for the new location. Mobile users returning to their primary locations see their usual default printers.

Printer driver installation delegated to users

In Windows Server 2008, administrators can now delegate to users the ability to install printer drivers by using Group Policy. This feature helps to maintain security by limiting distribution of administrative credentials.

What is the AD Recycle Bin? How do you use it?

Active Directory Recycle Bin helps minimize directory service downtime by enhancing your ability to preserve and restore accidentally deleted Active Directory objects without restoring Active Directory data from backups, restarting Active Directory Domain Services (AD DS), or rebooting domain controllers.

When you enable Active Directory Recycle Bin, all link-valued and non-link-valued attributes of the deleted Active Directory objects are preserved and the objects are restored in their entirety to the same consistent logical state that they were in immediately before deletion. For example, restored user accounts automatically regain all group memberships and corresponding access rights that they had immediately before deletion, within and across domains.

Active Directory Recycle Bin is functional for both AD DS and Active Directory Lightweight Directory Services (AD LDS) environments.

By default, Active Directory Recycle Bin in Windows Server 2008 R2 is disabled. To enable it, you must first raise the forest functional level of your AD DS or AD LDS environment to Windows Server 2008 R2, which in turn requires all forest domain controllers or all servers that host instances of AD LDS configuration sets to be running Windows Server 2008 R2.

To enable Active Directory Recycle Bin using the Enable-ADOptionalFeature cmdlet

1. Click Start, click Administrative Tools, right-click Active Directory Module for Windows PowerShell, and then click Run as administrator.

At the Active Directory module for Windows PowerShell command prompt, type the following command, and then press ENTER:

Enable-ADOptionalFeature -Identity -Scope -Target

For example, to enable Active Directory Recycle Bin for contoso.com, type the following command, and then press ENTER:

Enable-ADOptionalFeature –Identity ‘CN=Recycle Bin Feature,CN=Optional Features,CN=Directory Service,CN=Windows NT,CN=Services,CN=Configuration,DC=contoso,DC=com’ –Scope ForestOrConfigurationSet –Target ‘contoso.com’

What are AD Snapshots? How do you use them?

A snapshot is a shadow copy—created by the Volume Shadow Copy Service (VSS)—of the volumes that contain the Active Directory database and log files. With Active Directory snapshots, you can view the data inside such a snapshot on a domain controller without the need to start the server in Directory Services Restore Mode.

Windows Server 2008 has a new feature allowing administrators to create snapshots of the Active Directory database for offline use. With AD snapshots you can mount a backup of AD DS under a different set of ports and have read-only access to your backups through LDAP.

There are quite a few scenarios for using AD snapshots. For example, if someone has changed properties of AD objects and you need to revert to their previous values, you can mount a copy of a previous snapshot to an alternate port and easily export the required attributes for every object that was changed. These values can then be imported into the running instance of AD DS. You can also restore deleted objects or simply view objects for diagnostic purposes.

It does not allow you to move or copy items or information from the snapshot to the live database. In order to do that you will need to manually export the relevant objects or attributes from the snapshot, and manually import them back to the live AD database.

Steps for using Snapshot:

1. Create a snapshot:

open CMD.exe, Ntdsutil, activate instance ntds, snapshot, create, list all.

2. Mounting an Active Directory snapshot:

Before connecting to the snapshot we need to mount it. By looking at the results of the List All command in above step, identify the snapshot that you wish to mount, and note the number next to it.

Type Ntdsutil, Snapshot, List all, Mount 2. The snapshot gets mounted to c:\$SNAP_200901250030_VOLUMEC$. Now you can refer this path to see the objects in these snapshots.

3. Connecting an Active Directory snapshot:

In order to connect to the AD snapshot you’ve mounted you will need to use the DSAMAIN command. DSAMAIN is a command-line tool that is built into Windows Server 2008. It is available if you have the Active Directory Domain Services (AD DS) or Active Directory Lightweight Directory Services (AD LDS) server role installed.

After using DSAMAIN to expose the information inside the AD snapshot, you can use any GUI tool that can connect to the specified port, tools such as Active Directory Users and Computers (DSA.msc), ADSIEDIT.msc, LDP.exe or others. You can also connect to it by using command line tools such as LDIFDE or CSVDE, tools that allow you to export information from that database.

dsamain -dbpath ” c:\$SNAP_200901250030_VOLUMEC$\Windows\NTDS\ntds.dit” -ldapport 10289

The above command will allow you to access the database using port 10289.

Now you can useLDP.exetool to connect to this mounted instance.

4. Disconnecting from the Active Directory snapshot:

In order to disconnect from the AD snapshot all you need to do is to type CTRL+C at the DSAMAIN command prompt window. You’ll get a message indicating that the DS shut down successfully.

5. Unmounting the snapshot:

Run command, Ntdsutil, Snapshot, List all, Unmount 2.

What is Offline Domain Join? How do you use it?

You can use offline domain join to join computers to a domain without contacting a domain controller over the network. You can join computers to the domain when they first start up after an operating system installation. No additional restart is necessary to complete the domain join. This helps reduce the time and effort required to complete a large-scale computer deployment in places such as datacenters.

For example, an organization might need to deploy many virtual machines within a datacenter. Offine domain join makes it possible for the virtual machines to be joined to the domain when they initially start following the operating system installation. No additional restart is required to complete the domain join. This can significantly reduce the overall time required for wide-scale virtual machine deployments.

A domain join establishes a trust relationship between a computer running a Windows operating system and an Active Directory domain. This operation requires state changes to AD DS and state changes on the computer that is joining the domain. To complete a domain join in the past using previous Windows operating systems, the computer that joined the domain had to be running and it had to have network connectivity to contact a domain controller. Offline domain join provides the following advantages over the previous requirements:

The Active Directory state changes are completed without any network traffic to the computer.
The computer state changes are completed without any network traffic to a domain controller.
Each set of changes can be completed at a different time.

http://technet.microsoft.com/en-us/library/offline-domain-join-djoin-step-by-step%28WS.10%29.aspx

What are Fine-Grained Passwords? How do you use them?

You can use fine-grained password policies to specify multiple password policies within a single domain. You can use fine-grained password policies to apply different restrictions for password and account lockout policies to different sets of users in a domain.

For example, you can apply stricter settings to privileged accounts and less strict settings to the accounts of other users. In other cases, you might want to apply a special password policy for accounts whose passwords are synchronized with other data sources.

Talk about Restartable Active Directory Domain Services in Windows Server 2008/R2. What is this feature good for?

Restartable AD DS is a feature in Windows Server 2008 that you can use to perform routine maintenance tasks on a domain controller, such as applying updates or performing offline defragmentation, without restarting the server.

While AD DS is running, a domain controller running Windows Server 2008 behaves the same way as a domain controller running Microsoft® Windows® 2000 Server or Windows Server 2003.

While AD DS is stopped, you can continue to log on to the domain by using a domain account if other domain controllers are available to service the logon request. You can also log on to the domain with a domain account while the domain controller is started in Directory Services Restore Mode (DSRM) if other domain controllers are available to service the logon request.

If no other domain controller is available, you can log on to the domain controller where AD DS is stopped in Directory Services Restore Mode (DSRM) only by using the DSRM Administrator account and password by default, as in Windows 2000 Server Active Directory or Windows Server 2003 Active Directory.

Benefits of restartable AD DS

Restartable AD DS reduces the time that is required to perform offline operations such as offline defragmentation. It also improves the availability of other services that run on a domain controller by keeping them running when AD DS is stopped. In combination with the Server Core installation option of Windows Server 2008, restartable AD DS reduces the overall servicing requirements of a domain controller.

In Windows 2000 Server Active Directory and Windows Server 2003 Active Directory, you must restart the domain controller in DSRM when you perform offline defragmentation of the database or apply security updates. In contrast, you can stop Windows Server 2008 AD DS as you stop other services that are running locally on the server. This makes it possible to perform offline AD DS operations more quickly than you could with Windows 2000 Server and Windows Server 2003.

You can use Microsoft Management Console (MMC) snap-ins, or the Net.exe command-line tool, to stop or restart Active Directory® Domain Services (AD DS) in the Windows Server® 2008 operating system. You can stop AD DS to perform tasks, such as offline defragmentation of the AD DS database, without restarting the domain controller. Other services that run on the server, but that do not depend on AD DS to function, are available to service client requests while AD DS is stopped. An example of such a service is Dynamic Host Configuration Protocol (DHCP).

Windows Administrator L1 Interview Question

2015-03-02T17:48:00.001+05:30

1. What is the different between Workgroup and Domain? Domain Server has Centralized Control Where else Workgroup has no Centralized Control

Domain Network has higher level of security when compared to Workgroup.
Domain Network Implementation and Maintained cost is very less when compared to that of workgroup.
Time constrain is very less when compared to that of a Workgroup.
Administrator has overall control on the network where else workgroup has no control.

2. How will assign Local Administrator rights for domain user? Navigate to Local User and Groups add the domain users to administrators group in the local system.

3. How will you restrict user logon timing in domain?Navigate to Active Directory Users and Computers, User Properties select logon times and restrict the user logon timing as needed.

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, and groups 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.

Organization Unit is set of active directory object within a domain. It is used to design an organization structure, Restrict user’s visibility and to delegate control.

6. Explain different edition of windows 2003 Server?

Windows Server 2003, Standard Edition: - is aimed towards small to medium sized businesses. 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 and support for up to 32 GB of memory.
Windows Server 2003, Web Edition: - is mainly for building and hosting Web applications, Web pages, and XML Web Services.
Windows Server 2003, Datacenter Edition: - is the flagship of the Windows Server line and designed for immense infrastructures demanding high security and reliability.

7. What is DNS Server?

Domain Name System is used to resolve domain name to IP Address and also used to resolve IP Address to Domain Name. It has two zones Forward and Reverse Lookup Zone. Forward Lookup Zone resolve Domain name to IP address. Reverse Lookup Zone is used to resolve IP address to Domain Name. Some records associate with DNS

A Record binds Name with IP Address
PTR Record binds IP Address to Name

8. Why DNS server is required for Active Directory?

The key reason for integrating DNS with AD is that client server communication takes place with Domain Name. Network needs IP address to reach the destination; In order to resolve Domain Name to IP Address we need DNS Server. If DNS Server is not configured properly the network becomes slow.

9. What is the Purpose of A and PTR Record?

A Record OR Host Record is used to bind a Name with IP Address.
PTR Record is used to bind an IP Address with Name.

10. What is the purpose of DHCP Server?

DHCP Server is used to assign IP address automatically to all the clients’ computers. It is useful in large enterprise network, where we may not able track the IP address and also used to avoid IP conflict.

11. Explain about Scope in DHCP Server?

Scope is collective information of assigning IP address for clients. It contains information like IP Address Range, Exclusion Range, Lease Period, Reservation, Router IP Address, DNS Address, etc. Based on the scope configuration DHCP allocates IP address to its entire client.

12. Explain about Group Scopes?

13. How will you backup DNS Server?

Backup the directory “%System Root%\System32\DNS”.

14. How will backup DHCP Server?

First Method: Backup the directory in the %System Root%\System32\DHCP folder.

Alternate method: Open DHCP Console select server to backup and restore DHCP database.

15. 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).

16. Explain about AD Database.

Windows 2003 Active Directory data store, the actual database file, is %System Root%\NTDS\NTDS.DIT. AD Database all information such as User Accounts, Groups, Computer Information, Domain Controller information, Group Policy, Organization Unit,etc.

17. 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) .There is a maximum of 1000 applicable group policies.

18. 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.

19. Explain Hidden Share.

Hidden or administrative shares are share names with a dollar sign ($) appended to their names. Administrative shares are usually created automatically for the root of each drive letter. They do not display in the network browse list.

20. What ports are used by DHCP and the DHCP clients?

Requests are on UDP port 68, Server replies on UDP 67.

21. How do I configure a client machine to use a specific IP Address?

By reserving an IP Address using client machine MAC or Physical address.

22. Name 3 benefits of using AD-integrated zones.

AD Integrated Zones allow Secure Dynamic Updates. I.e. there will not be any duplicate or unwanted records. Since all the information are validated in active directory.
By creating AD- integrated zone you can also trace hacker and spammer by creating reverse zone.
AD integrated zones are stored as part of the active directory and support domain-wide or forest-wide replication through application partitions in AD.

23. How do you backup & Restore AD?

Using Windows NTBackup Utility. In Backup select systemstate will include active directory backup. Restore the Same using NTBackup Utility.

24. How do you change the DS Restore admin password?

Using NTDSUTIL tool.

25. How can you forcibly remove AD from a server?

Using the command dcpromo /forceremoval

26. What will be the problem if DNS Server fails?

If your DNS server fails, No Client will able to reach the Domain Controller, which will create authentication and Control Issues.

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?

Using the command dcpromo

29. How will map a folder through AD?

Specify the network share path (UNC) in the active directory users home directory.

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.
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.

Navigate to Active Directory Users and Computers, Create new printer and add the printer i.e. the printer share name (UNC) Path. Automatically the printer will be published in Active Directory.

33. Explain the functionality of FTP Server?

File Transfer Protocol is used transfer large volume of files and huge number of files simultaneous between different geographic locations.

34. Specify the Port Number for AD, DNS, DHCP, HTTP, HTTPS, SMTP, POP3 & FTP

AD - 389
DNS - 53
DHCP - 67,68
HTTP - 80
HTTPS - 443
SMTP - 25
POP3 - 110
FTP - 21,22

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 hold a range IP addresses. Those IP Address can be used or may not be used in the network, but DHCP server does not assign those IP to its client.

37. Explain SOA Record.

Start Of Authority (SOA) Records indicate that Name Server is authoritative server for the domain.

38. What command is used to clear DNS cache in client PC?

Ipconfig /flushdns

39. Explain Secure Dynamic Updates in DNS Server.

Only when installing active directory and DNS in the same server (AD Integrated Zones) we can select Secure Dynamic Updates. Then all the records will automatically be updated in DNS. Since all the information is validated in active directory there will not be any duplicate or unwanted records.

40. Explain FRS in detail.

File Replication Service is a Microsoft service which replicates folders stored in sysvol shared folders on domain controllers and distributed file system shared folders. This service is a part of Microsoft’s active directory service.

41. Explain the protocol involved in ADC replication.

Remote Procedure Call (RPC) is the protocol used in ADC replication.

42. Explain the difference between Patches and Service pack.

Patches are fixes, updates or enhancements for a particular program whereas service packs include a collection of

43. What is WSUS?

WSUS is Windows Software Update Services. It is server provided by Microsoft free of cost to manage patches for windows environment centralized.

44. How client server communication takes place in WSUS server?

Using Web Server or Web Services

45. What is the difference between Dynamic Disk and Basic Disk?

Basic Disk: Basic Disk uses a partition table to manage all partitions on the disk, and it is supported by DOS and all Windows versions. A disk with installed OS would be default initialized to a basic one. A basic disk contains basic volumes, such as primary partitions, extended partition, and all logical partitions are contained in extended partition.

Dynamic Disk: Dynamic Disk is supported in Windows 2000 and later operating system. Dynamic disks do not use a partition table to track all partitions, but use a hidden database (LDM) to track information about dynamic volumes or dynamic partitions on the disk. With dynamic disks you can create volumes that span multiple disks such as spanned and striped volumes, and can also create fault-tolerant volumes such as mirrored volumes and RAID 5 volumes. Compared to a Basic Disk, Dynamic Disk offers greater flexibility.
46. What is maximum Size of file system NTFS and FAT32?

NTFS - 16TB

FAT32 - 4GB

47. What is “hosts” files?

The hosts file is a computer file used in an operating system to map hostnames to IP addresses. The hosts file is a plain-text file and is traditionally named hosts.

48. What is “lmhosts” files?

The lmhosts files are a computer file used in an operating system to map NetBIOS name. It is equivalent that of WINS.

49. Explain About Global Catalog.

global catalog contains a complete replica of all objects in Active Directory for its Host domain, and contains a partial replica of all objects in Active Directory for every other domain in the forest.

50. Name some OU design considerations.

It is used to design an organization structure, Restrict user’s visibility and to delegate control.

51. Name a few benefits of using GPMC.

GPMC is used to customize group policy.

It is easy to maintain different OU policy effectively.
Provide option to take backup and restore group policy.

52. You want to standardize the desktop environments (wallpaper, My Documents, Start menu, printers etc.) on the computers in one department. How would you do that?

Configure Group Policy based on OU.

53. By default, if the name is not found in the cache or local hosts file, what is the first step the client takes to resolve the FQDN name into an IP address?

Create a record in DNS Server

54. You are administering a network connected to the Internet. Your users complain that everything is slow. Preliminary research of the problem indicates that it takes a considerable amount of time to resolve names of resources on the Internet. What is the most likely reason for this?

DNS Issues

55. Describe how the DHCP lease is obtained.

It’s a four-step process consisting of (a) IP request, (b) IP offer, (c) IP selection and (d) acknowledgement.

56. I can’t seem to access the Internet, don’t have any access to the corporate network and on ipconfig my address is 169.254.*.*. What happened?

The 169.254.*.* netmask is assigned to Windows machines running 98/2000/XP if the DHCP server is not available. The name for the technology is APIPA (Automatic Private Internet Protocol Addressing).

57. We’ve installed a new Windows-based DHCP server, however, the users do not seem to be getting DHCP leases off of it.

The server must be authorized first with the Active Directory.

58. How do you configure mandatory profiles?

Rename ntuser.dat to ntuser.man

59. What is Page File and Virtual Memory?

Page File Is Storage Space For The Virtual Memory, Page File Uses Hard Disk Space As a Memory To Provide Memory Allocation...

60. What is the difference between DNS in Windows 2000 & Windows 2003 Server?

We can rename or moved the domain name without rebuilding in windows 2003 server, but in windows 2000 server, we can't do that.

61. Where are group policies stored?

%SystemRoot%System32\Group Policy

62. What are GPT and GPC?

Group policy template and group policy container.

63. Where is GPT stored?

%System Root%\SYSVOL\sysvol\domain name\Policies\GUID

64. You change the group policies, and now the computer and user settings are in conflict. Which one has the highest priority?

The computer settings take priority.

65. What hidden shares exist on Windows Server 2003 installation?

Admin$, Drive$, IPC$, NETLOGON, print$ and SYSVOL.

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recimg – Create Custom Recovery Images

wbadmin start backup – Create System Recovery Images

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Infrastructure Master

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