Network and System Administration Questions

Network Interview Questions and Answers

Q:What is Networking?

Inter connection between the two or more computers is called the networking. Using three types of network are Intranet, Internet and Extranet (Eg. LAN, WAN & MAN)

Q:What is Bandwidth?

Every line has an upper limit and a lower limit on the frequency of signals it can carry. This limited range is called the bandwidth. Every line has a capacity of transmission of data, The maximum amount of data that can be transferred in a single line is called Bandwidth.

Q:What is VLAN?

VLAN Stand for Virtual Local Area Network. It is a logical grouping of network users and resources connected to administratively defined ports on a switch.
Uses of VLAN are as follows:-

1. It is securied connection.
2. It increases flexibility.
3. It creates separate broadcast domain.

Q:What is CIDR?

CIDR Stands for classless inter domain routing. It helps in preventing the wasting of IP address and nowadays we are facing the shortage of the IP address.So this CIDR helps to prevent the waste of IP address.Shortly IPV6 will come into exist.

Q:What is VLSM?

VLSM stands for Variable length subnet mask, when try to separate a major subnet into minor ones, then that process is called VLSM. We can subnet in various lengths.
Eg: 1.1.1.0-/24 can be separated into 1.1.1.0-/30 and 1.1.1.4-/28

Q:What is unicast?

Unicast is one type of transmission in which information is sent from one host to another host (i.e Source to Destination). In another words, Unicast transmission is between one-to-one nodes

Unicast ---> A transmission to a single interface card.

Q:What is Multicast?

Multicast is such differ from Unicast. It is another type of transmission or communication in which there may be more than host and the information sent is meant for a set of host.(i.e one source to group of destination

Multicast ---> A transmission to a group of interface cards on the network.

Q:What is Broadcast?

Broadcast is one type of transmission in which information is transfer from just one host but is received by all the host connected to the network. (i.e one source to all destination)

Broadcast ---> A transmission to all interface cards on the network.

Q:What is CDP?

CDP Stand for Cisco Discovery Protocol, It's a Layer 2 protocol and used to check the availability of neighbouring Cisco devices. It can give you all the details of the neighbours. CDP provides network device inventory, connectivity information, and IP next hop information. CDP Version-2 (CDPv2) is the most recent release of the protocol and provides more intelligent device tracking features.

Sending CDP packets every 60 seconds and

Hold time is 180 seconds.

Q:What is SNMP?

The Simple Network Management Protocol (SNMP) is an application layer protocol (Layer 1) that facilitates the exchange of management information between network devices. It is part of the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol suite. SNMP enables network administrators to manage network performance, find and solve network problems, and plan for network growth.

What is OSPF?

Open Shortest Path First (OSPF) is a dynamic routing protocol for use in Internet Protocol (IP) networks. OSPF is designated by the Internet Engineering Task Force (IETF). Specifically, it is a link-state routing protocol and falls into the group of interior gateway protocols, operating within an autonomous system (AS). Unlimited router can be used. CPU usage will be high, to reduce the CPU Usage using area.

What are the areas in OSPF?

• The backbone area, which is also referred to as Area 0. All other areas must connect to the backbone area. Hence, this area is obligatory.

• An ordinary or standard area, which is an area that connects to the backbone (Area 0) and is treated as a separate entity. All routers in a standard area have the same topological database, but their routing tables will be based on the routers position in the standard area and will thus be unique to the router.

• A stub area, which is an area that does not accept external summary routes. A router within a stub area can only see outside the autonomous system if a default route has been configuration for it.

• A totally stubby area, which is similar to a stub area. In this area, the default route must be configured as 0.0.0.0. This type of area is useful for remote sites that have few networks and limited connectivity with the rest of the network and is a Cisco proprietary solution.

• A not so stubby area (NSSA), which is a stub area that can receive external routes but will not propagate those external routes into the backbone area.

What are the network types in OSPF?

1. Non broadcast - This is the default on frame relay networks has a DR/BDR election.  Neighbor command needed to establish adjacency.

2. Broadcast - This is the default on Ethernet/broadcast networks.  Does have DR/BDR election.

3. Point-to-point -  No DR/BDR election.  This one is pretty self explanatory.

4. Point-to-multipoint - Does not have a DR/BDR election. Solves some design issues with the next hop processing for NONBROADCAST.  Treats as a collection of P2P links.

5. Point-to-multipoint non broadcast - Same as P2M but does not use pseudo broadcast.  Must statically define neighbors.

6. Loopback - OSPF treats these as stub hosts. (/32)

What is RIP and difference between Rip V1 & Rip V2?

RIP Stands for Routing information protocol. It is also called distance vector routing protocol. It is open standard for any vendor use. It uses metric as hop count (max hop count 15) AD 120. It sends periodic update for every 30 sec. It is used for small network.

Rip V1 1. It is a Class full Protocol. 2.Classful Protocol: - Supports networks with same Subnet Mask 3.RIPV1 uses Broadcast Address 4.RIPV1 Universal Broadcast (255.255.255.255) 5. RIPV1 does not VLSM.

Rip V2 1. It is a Classless Protocol. 2.Classless Protocol: - Supports subnetted networks; It carries the information of   subnet mask 3.RIP V2 uses Multicast Address 4. RIPV2 uses Multicast (224.0.0.9). 5.RIPV2 supports VLSM

What are BGP and their attributes?

The Border Gateway Protocol (BGP) is an inter autonomous system routing protocol. An autonomous system is a network or group of networks under a common administration and with common routing policies. BGP is used to exchange routing information for the Internet and is the protocol used between Internet service providers (ISP). Customer networks, such as universities and corporations, usually employ an Interior Gateway Protocol (IGP) such as RIP or OSPF for the exchange of routing information within their networks. Customers connect to ISPs, and ISPs use BGP to exchange customer and ISP routes. When BGP is used between autonomous systems (AS), the protocol is referred to as External BGP (EBGP). If a service provider is using BGP to exchange routes within an AS, then the protocol is referred to as Interior BGP (IBGP).

BGP Attributes  are 1. Weight                                              5. AS_path 2. Local preference                                 6. Next hop 3. Multi-exit discriminator                         7. Community 4.Origin

What is PPPoE?

Point to Point Protocol over Ethernet (PPPoE) is network protocols that allow data communication between two network entities or points, which supports network layer protocols including IPv4 and IPv6. PPP supports three types of user authentication protocols that provide varying levels of security.

1.             PAP                          2.  CHAP                                3.  EAP

PAP	CHAP
1. Clear text	1. Encrypted
2. Less secure	2. High secure
3. Two way handshake method	3. Three way handshake method
Auth. Request	Challenge
Auth. Acknowledgment	Response
	Success
4. No periodic Check up	4. Periodical Check up

Extensible Authentication Protocol (EAP) is most commonly used for authentication on wireless networks

What are the timers for dynamic routing protocol? Rip IGRP EIGRP OSPF Hello None None 60 sec 10 sec Update timers 30 sec 90 sec Dead timers 180 sec 3*hello 3*hello 4*hello What is the AD Value for Dynamic routing protocols? Rip IGRP EIGRP OSPF BGP AD 120 100 90 110 20

Windows Desktop Interview Questions and Answers

>How to Enable or Disable the Firewall in Windows XP ?

Enabling the Windows XP firewall

1.             Click Start, Settings, Control Panel and open Network Connections.

2.             Within the Network Connections window, right-click the Local Area Connection and select properties.

3.             Within the Local Area Connection Properties window, click the Advanced tab.

4.             Finally, check the Protect my computer and network by limiting or preventing access to this computer from the Internet option.

>Disabling the Windows XP firewall ?

1.             Click Start, Settings, Control Paneland open Network Connections.

2.             Within the Network Connections window, right-click the Local Area Connection and select Properties.

3.             Within the Local Area Connection Properties window, click the Advanced tab.

4.             Finally, uncheck the Protect my computer and network by limiting or preventing access to this computer from the Internet option.

> How would you Start or Stop a Windows Service ?

Logon to Windows with Administrator rights.
Click Start > Control Panel.
Double-click Administrative Tools.
Double-click the Services icon.
Double-click the service that you want to stop or start.
When the Service Properties window appears, do one of the following:

* If the service is running, click Stop the service.
* If the service is not running, click Start the service.

Click OK.

> How can you check the IP address of your computer ?

IPCONFIG /ALL


> How to access the Windows System Registry ?

Follow the steps to access registry on XP computer.
* Click Start
* Click Run
* Type REGEDIT
* Click OK
* The Registry Editor will now open .

> Where are the Temp files located and how would you remove them ?

There are three different places that you can find temporary files on your computer. They are located in different place in Windows Vista and Windows Xp. In Windows Vista there are three file paths below to follow to view the temporary files.

C:\Users\Username\AppData\Local\Temp (%temp)

C:\Windows\Temp (temp)

C:\Users\Username\AppData\Local\Microsoft\Windows\Temporary Internet Files

> Name some difference between Windows XP and Windows Vista. What are their System Requirements ?

The major Differences between Windows Xp & Vista are :


Windows Vista & Windows XP

1. Bitlocker Option available Windows XP has . No Bitlocker option
- Bitlocker drive encryption, Bitlocker on volume Prevents hard drive from hackers.

2. Windows Vista has Windows Defender tool Windows XP has No Windows Defender tool available - prevents from spyware & unwanted S/W installing on computer.

3. Windows Vista has Parental control Feature Windows XP has No Parental control Feature - This option enables parents to restrict Children’s which sites, games .software to use & not .

> What is Safe Mode ?

Safe mode is an alternate boot method for Windows operating systems that makes it easier to diagnose problems. The only startup programs loaded are the operating systemand drivers for the mouse, keyboard, and display modes display. It is often possible to get a system to start in safe mode when it won't start normally. To start in safe mode, press the F8 key while the system is booting and select "safe mode" (or the safe mode option you want) from the menu that appears.

>What is Last Known Good Configuration ?
The Last Known Good configuration" is one of the methods which are used to repair our computer system. In this method a restore of data from the backup is not required. This "last known good configuration" is a backup replica of the existing configuration which is stored on the registry key "HKLM\System\CurrentControlSet". This registry key is always updated whenever the system is shut down by the user after successfully and effectively logging on. Our system can be repaired by restoring information from this updated registry key. For instance in case when we install some driver which causes our operating system not to be loaded, this type of repair is helpful and useful.
So it is a very good practice to repair our system without any loss. So whenever we see our operating systemfails to load, simply press F8 and when the message "please select the operating system to start" appears, just select the Last Known Good Configuration. This option can be seen under the "Windows Advanced Options Menu". The Last Known Good Configuration is only useful in the case if we have not logged on yet. Whenever we logon and then shut down or even restart, all of the current configurations always become the "Last Known Good Configuration".

>What is windows Device Manager ?
Device Manager is an extension of the Microsoft Management Console that provides a central and organized view of all the Microsoft Windows recognized hardware installed in a computer.

Device Manager is used to manage the hardware devices installed in a computer like hard disk drives, keyboards, sound cards, USB devices, and more.

>What is MSConfig ?
msconfig.exe is a file which helps to edit and administer text configuration files such as win.ini and autoexec.bat.

Msconfig is used to control what programs and services start with your computer. Its very helpful in troubleshooting startup problems as well as poor performance and getting rid of spyware and viruses.

>What is the Blue Screen of Death and what could be it's causes ?
Sometimes bad or flaky memory (RAM memory, not your hard drive) can cause seemingly random system crashes. If you have just the right combination of programs open and system memory in use, and your computer tries to access a "bad spot" on a RAM chip, the results can be unpredictable. Or they can be the Blue Screen of Death. You can try replacing your RAM sticks one at a time to see if the problem goes away. This involves opening up the system unit and looking at scary wires and stuff, so for some people just living with the problem may be a workable option.

More likely, you have a software problem. Some programs just don't get along... they trample on each other's memory spaces and confusion (or the BSOD) results. And it seems that Windows just gets old and cranky the longer you have it installed. You may solve the problem by using the System File Checker, or if all else fails, by
re-installing the Windows operating system and/or your software packages. If the problem seems to be limited to one particular program, try re-installing just that one first.

Spyware or a computer virus can also make strange things happen.

> What is Cold Boot and Warm Boot ?
A cold boot means turning it on from a powered-down state. A warm boot is pressing the restart button when the computer is already on.

> What is Disk Cleanup?
Disk Cleanup is a feature of Windows that enables a user to delete system / junk files safely.
For example, by using the disk cleanup feature, you can free up a considerable amount of space on your pc, like getting rid of TIF (Temporary Internet Files) and other 'useless', and not required, files.

> What is Disk Defragmentation?
Disk defragmentation describes the process of consolidating fragmented files on your computer's hard disk.

Fragmentation happens to a hard disk over time as you save, change, or delete files. The changes that you save to a file are often stored at a location on the hard disk that's different from the original file. Additional changes are saved to even more locations. Over time, both the file and the hard disk itself become fragmented, and your computer slows down as it has to look in many different places to open a file.

Disk Defragmenter is a tool that rearranges the data on your hard disk and reunites fragmented files so your computer can run more efficiently. In this version of Windows, Disk Defragmenter runs on a schedule so you don't have to remember to run it, although you can still run it manually or change the schedule it uses.

> What would you do if a PC is not turning on ?First Check the Power cables and power supply.

> What is the latest Operating System ?
Windows 7.

> What is a Heat Sink ?
A component designed to lower the temperature of an electronic device by dissipating heat into the surrounding air. All modern CPUs require a heat sink. Some also require a fan. A heat sink without a fan is called a passive heat sink; a heat sink with a fan is called an active heat sink. Heat sinks are generally made of an aluminum alloy and often have fins.

> What is the difference between SATA and PATA Hard-Disk Drives?
Serial ATA and Parallel ATA are both specialized interface and data transfer devices, that are used in computers to connect peripheral storage devices. Both serve the same purpose of data transfer but differ in their basic technology, speed of performance and therefore their niche applications these days.

> What would you do if your system is running slow ?
1.Empty Recycle Bin.
2.Empty Windows Temp folder.
3.Run Scandisk.
4.Run Defragmenter.
5.Full System Virus scan.

> What are Plug & Play devices ?
They are peices of computer hardware that already have the software for them in you system. simply put, you just have to plug it in and you computer does the rest.

> What are Device Drivers?
Device drivers are small files that act like “liaisons” between hardware in a computer system and the operating system (OS). Hardware requires device drivers so that the OS can “see” the devices and handle them effectively and efficiently.

> Difference between IE6 & IE7 ? 
ie 6-security issuse are less
ie 7-security issuse are more.

ie 6-tabbed browsing is not there
ie 7-tabbed browsing is available.

ie 6-no advanced printing.
ie 7- advanced printing.

ie 6-no phishing filter.
ie 7-phishing filter available.

ie 6-no tool bar search box.
ie 7- tool bar search box.

ie 6-no advanced delete history.
ie 7-advanced delete browing history option.

ie 6-no page zoom.
ie 7-page zoom.

ie 6-no add-ons disable mode
ie 7-add-ons disable mode.

> What is the difference between a Serial and a Parallel Port ?
Basically a serial port sends and receives data 1 'bit' at a time over a single wire, while a parallel port sends the data a 'byte' at a time over several wires simultaneously.

> Explain the Windows XP Boot Process ?
1.First is the POST, this stands for Power On Self Test, for the computer. This process tests memory as well as a number of other subsystems. You can usually monitor this as it runs each test. After that is complete the system will run POST for any device that has a BIOS (Basic Input-Output System). An AGP has its own BIOS, as do some network cards and various other devices.

2.Once the POST is complete and the BIOS is sure that everything is working properly, the BIOS will then attempt to read the MBR (Master Boot Record). This is the first sector of the first hard drive (called the Master or HD0). When the MBR takes over it means that Windows is now in control.

3.The MBR looks at the BOOT SECTOR (the first sector of the active partition). That is where NTLDR is located, NTLDR is the BOOT LOADER for Windows XP. NTLDR will allow memory addressing, initiate the file system, read the boot.ini and load the boot menu. NTLDR has to be in the root of the active partition as do NTDETECT.COM, BOOT.INI, BOOTSECT.DOS (for multi-OS booting) and NTBOOTDD.SYS (if you have SCSI adapters)

4.Once XP is selected from the Boot Menu, NTLDR will run NTDETECT.COM, BOOT.INI and BOOTSECT.DOS to get the proper OS selected and loaded. The system starts in 16-bit real mode and then moves into 32-bit protected mode.

5.NTLDR will then load NTOSKRNL.EXE and HAL.DLL. Effectively, these two files are windows XP. They must be located in %SystemRoot%System32.

6.NTLDR reads the registry, chooses a hardware profile and authorizes device drivers, in that exact order.

7.At this point NTOSKRNL.EXE takes over. It starts WINLOGON.EXE that in turn starts LSASS.EXE, this is the program that display the Logon screen so that you can logon.

> What do you know about the PING Command ?
Pinging is a command which tells you if the connection between your computer and a particular domain is working correctly.

Eg : C:\Administrator\>Ping 192.168.1.100 or Ping server.domain.com

Regards,

Anand