List Of 100 Computer Networks Interview Questions

Q – 1 Can a machine with a single DNS name have multiple IP addresses? If yes then how could this occur?

Ans- yes it can happen. DNS, the Domain Name Service, as you would know, is used to help us resolve Fully Qualified Domain Names (FQDN) to IP addresses. There are different versions of DNS systems running all over the Internet, mainly ranging between Windows (which use the Windows DNS server) and Linux/Unix (using BIND DNS services).

Considering there are some very popular Web sites which serve millions of DNS queries per day e.g., Google.com, Hotmail.com, it is logical that these domain names cannot solely rely on one single DNS server, cause if that fails, the whole domain could become unreachable! It is, for this reason, a fault-tolerant DNS service is put in place, which shares the DNS queries amongst several different DNS servers.

All servers are configured to either randomly provide clients with IP addresses from a specific pool, or — by using a round robin method — cycle between the pool of IP addresses. This is what gives a DNS name multiple IP addresses.

Q – 2 Explain what is file system? How a file is organized in file system? Give few examples?

Ans- File system is depending on Operation systems & hard Disk sizes.At the time 1990 there were only dos which supports only FAT16 (File allocation table)Upto MS-DOS 6.22 & Windows 3.1 & 3.11 It works only on FAT16FAT16 Has it’s limitation that it can’t support more than 2.1 GB partition at a time.After that windows 95 & Windows 98That supported FAT16 & FAT32 only. Windows NT supports FAT16 as well as It develops new file systems HPFS i.e. (High Performance File System)
Later i.e. is called as NTFS (New Technology File System)NTFS is now a largest support for us.

Q – 3 Tell me what is a VLAN? What does VLAN provide?

Ans- Short for virtual LAN, a network of computers that behave as if they are connected to the same wire even though they may actually be physically located on different segments of a LAN VLANs are configured through software rather than hardware, which makes them extremely flexible.

One of the biggest advantages of VLANs is that when a computer is physically moved to another location, it can stay on the same VLAN without any hardware reconfiguration.

Q – 4 How to recover deleted file from network?

Ans- It remains in the recycler on the drive or partions the held that data untill it is overwriten. To view the recycler you must allow hiden system files to be shown (in Windows this can be done under folder options). There are tool available to recover the deleted data. I recently have used a program call “Recover My files”.

Q – 5 Explain what is difference between ARP and RARP?

Ans- The address resolution protocol (ARP) associates an IP address with the physical address. On a typical physical network (eg: LAN) each device on a link is identified by a physical or station address usually imprinted on the network interface card(NIC)Physical addresses can be changed easily, on the other hand IP addresses cannot be changed. ARP is used to find the physical address of the node when its internet address is known.

The reverse address resolution protocol(RARP) allows host to discover its internet address when it known only its physical address. RARP works much like ARP.

To obtain IP address the host first broadcasts an RARP request packet containing its MAC address on the network. All hosts on the network receive the packet, but only the server replier to the host by sending an RARP response packet containing the host’s MAC and IP addresses.

One limitation with RARP is that the server must be located on the same physical network as the host

Q – 6 What is difference between TCP protocol& UDP protocol?

Ans- The difference between TCP and UDP is connection(TCP) and connectionless(UDP) protocol.Because In TCP for transferring every Packets it needs a acknowledgement packet from reciever ,so if any packet loss happens reciver will not send a acknowledge ment for that packet so Transmitter will once again send the packet.so TCP is reliable connection unless UDP will send a packet and will not expect any acknowledgment from the reciever so it is not reliable.

Q – 7 What do you need to know to set up a network?

Ans- First u need to specify your network size. Since the network eqiuipments depend upon your sixeeg:
Small network u could use as a l2 switch large network a l3/managed switch.

Same goes for routers and Wan connection.Servers:

1.Active Domain Controller
2.Back up Domain Controller.
3.Dhcp server.
4.Software Update services.
Hope this would suffice…

Q – 8 Explain Full form of SATA hard disk?

Ans- Serial Advanced Technology Attachment ( is a computer bus primarily designed for transfer of data between a computer and mass storage devices such as hard disk drives and optical drives.The main advantages over the older parallel ATA interface are faster data transfer, ability to remove or add devices while operating (hot swapping), thinner cables that let air cooling work more efficiently, and more reliable operation with tighter data integrity checks.

Q – 9 How to share a printer?

Ans- This is how I share a printer on a the LAN You can print from every PC on your network to one printer. To share a printer with the other PCs in your home you need to configure the PC to which the printer is connected and then install the shared printer on each PC that you want to print from.If you have not already done so, set-up and install the printer onto a PC following the manufacturer’s instructions.

The following instructions will vary slightly depending on which version of Windows you are using.1. Turn on all of the PCs on your network and turn on the printer.2. Start with the PC to which the printer is connected. Click Start, Settings, Control Panel, Printers.3. In the Printers window, right click on the printer that you want to share on the network and choose “Sharing” from the menu.4. If this is the first time anything has been set-up for sharing on this PC, you may receive a security warning.

In the security message, click on “Just enable printer sharing” and then click “OK”. Otherwise click on “Share this printer”.5. Enter a share name, something like “Laser printer in office”. 6. Now click “OK”.

Q – 10 Tell us which osi layer participate in Bandwidth?

Ans- Data link layer/Transport layer

Q – 11 What is difference between encoding and modulation? please give me detail of encoding and modulation?

Ans- Encoding is assigning binary codes according to algorithm, but modulation is changing the properties of one signal(value) according to properties of another signal.

Q – 12 Explain about Scan Disk? How scan disk fixes errors?

Ans- Scandisk is Windows’ general-purpose hard drive diagnostic utility. It will find and fix any data errors present on the drive. A “standard” scan checks for any data errors on the drive. A “thorough” scan checks for any data errors on the drive and tests the hard drive for any physical errors. Defrag is Windows’ utility for organizing the data structure on the hard drive. Through normal use, the data present on the hard drive becomes scattered across the data area.

Q – 13 What you will do, if you computer boots to the black screen?

Ans- 1) Check cable between computer and monitor, as well as power to monitor.
2) Boot into safemode – Check status of driver, and run diagnostic on video card. – if no video try putting in a new video card and restart with step 2
3) Restore to previous bootable configuration
4) Re-install OS

Q – 14 Explain what is the routed protocols & routing protocols?

Ans- A routing protocol is used by router to dynamically find all the networks in the internetwork and to ensure that all routers have the same routing table. Basically routing protocol determines the path of a packet through an internetwork. (eg. RIP, RIPv2, EIGRP and OSPF).A routed protocol can be used to send user data through the established enterprise, when routers know about all networks. Routed protocols are assigned to an interface and determine the method of packet delivery. (eg. IP, IPv6)

Q – 15 What is the difference between simplex and duplex?

Ans- simplex- one way transmission.only transmission will takes place here.
duplex- two way transmission.
Both transmission and reception takes place.

2 types of duplex:

1)Half duplex
2)Full duplex

Half duplex:-

both transmission and reception takes place,bt nt at d same time.single channel is used .

Full duplex:-

both txn and recep…takes place simultaneously using 2 different channels. one for txn and other 4 reception.

Q – 16 What is a SEGMENTED NETWORK?

Ans- Seagment is a PDU (Packet Data Unit) of layer 4 transport layer.seagmant is made of
destination port no
senders port no
data
fcs

Q – 17 What is the size of ping to death packet?

Ans- A ping is normally 64 bytes in size.Many computers can not handle larger than the maximum ip packet size, which is 65,535bytes. Sending a ping of this size can crash the target computer.

Q – 18 What is ping to death packet?

Ans- POD (Ping of Death) is a type of attack at computer in a network that involves sending of a larger size malicious ping to a computer.

Q – 19 What is Active Directory in Computer Networks?

Ans- Active Directory is a directory service. The term directory service refers to two things – a directory where information about users and resources is stored and a service or services that let you access and manipulate those resources. Active Directory is a way to manage all elements of your network, including computers, groups, users, domains, security policies, and any type of user-defined objects.

It melds several NT services and tools that have functioned separately so far – User Manager for Domains, Server Manager, Domain Name Server – and provides additional functions beyond these services and tools. Active Directory is built around Domain Name System (DNS) and lightweight directory access protocol (LDAP) – DNS because it is the standard on the Internet and is familiar, LDAP because most vendors support it.

Active Directory clients use DNS and LDAP to locate and access any type of resource on the network. Because these are platform-independent protocols, Unix, Macintosh, and other clients can access resources in the same fashion as Windows clients.

Q – 20 Explain in detail about the working of SWITCH in Networking?

Ans- Switch is a data link layer device that connect multiple LAN segments to form a single network segment. In switch when we transmit the data first it examine the data packets for source and destination, then the switch forward the data packet to the appropriate destination.

Switch minimize the possibility of collision of data packets by reducing collision domains. Collision domain are the network segment between two network devices, when the two devices transmit a data at a time then collision will occur. In such case both the device stop working.

Then it starts to work for a specific period of time and retransmit the data. Switches reduces the collision using micro-segmentation.

Q – 21 What is the default subnet mask for IPV6?

Ans- There are 3 address types in v6 – Unicast, anycast, and multicast. Unicast addresses identify a single network device, anycast and multicast addresses identify a group of network devices. IPv6 addresses are 128 bit, compared to the 32 bit addresses of v4 and look like this example – 2001:0db8:85a3:08d3:1319:8a2e: 0370:7348Ipv6 does not use subnetting.

Q – 22 What is the difference between physical address and logical address?

Ans- Logical address of yhe any nic card is ip address of the sysytem.in any copmany lan or wan environment for machine to mechine communication each and every mechine required one nomber.thats why ina peoples desizned and interduces one good technologie is ip addressing system.

phisical address of any copmany nic card is also known as a mac address {media accec controler address} mac address mediater bitween cable and mechine. it means mac address main function is transfer the data cable laguage to mechine language anad mechine language to cable language.its a 48 bit address

Q – 23 What are the Advantages and Disadvantages of DHCP?

Ans- Advantages All the IP configuration information gets automatically configured for your client machine by the DHCP server. If you move your client machine to a different subnet, the client will send out its discover message at boot time and work as usual.

However, when you first boot up there you will not be able to get back the IP address you had at your previous location regardless of how little time has passed. Disadvantage Your machine name does not change when you get a new IP address. The DNS (Domain Name System) name is associated with your IP address and therefore does change. This only presents a problem if other clients try to access your machine by its DNS name.

Q – 24 What is port address in Computer Networks?

Ans- A port number is a way to identify a specific process to which an Internet or other network message is to be forwarded when it arrives at a server. For the Transmission Control Protocol and the User Datagram Protocol, a port number is a 16-bit integer that is put in the header appended to a message unit. This port number is passed logically between client and server transport layers and physically between the transport layer and the Internet Protocol layer and forwarded on.

Q – 25 Do you know what is difference between baseband and broadband transmission?

Ans- Baseband Signalling:

1)Uses digital signalling
2)No frequency-division multiplexing
3)Bi-directional transmission
4)Signal travels over short distances

Broadband Signalling:

1)Uses analog signalling
2)Unidirectional transmission
3)Frequency-division multiplexing is possible
4)Signal can travel over long distances before being attenuated

Q – 26 Explain what is Printer driver replication and mapping?

Ans- Printer driver replication means if you have a network printer and if you want to share it among other Citrix servers, then we can replicate that driver to be used by all the Citrix servers or for few selected Citrix servers, however that driver should be installed in the Citrix server from which we are replicating the driver.

Printer mapping relates to mapping the driver software for specific domain users only, these can be dont by right clicking on the driver or by the printer option on the left plane of Citrix presentation server console.

Q – 27 What is ost file?

Ans- In Microsoft Office Outlook 2003, a new offline folder file format is introduced that offers greater storage capacity for items and folders and supports multilingual Unicode data. An offline file folder is used to keep a local copy of your Exchange Server mailbox on your computer.

The items in your .ost file are synchronized with the server when a connection is available.Steps for offline file folder:-1. On the File menu, click Work Offline. 2. Select or clear the Prompt me at startup so I may choose to work offline or online check box, and then click OK. If you clear the check box, Outlook will automatically start offline if a connection to the server is not available.3. Click Yes to copy the data from the server to your new Offline Folder file (.ost).

Q – 28 What is the difference between networking and telecom domain ? Will network protocol testing will come under telecom domain?

Ans- Please share your answers.

Q – 29 Tell me how to transfer some data periodically using RTP protocol without any loss?

Ans- Suppose i want to send some periodic information during the normal voip communication using RTP. How can I make sure that this data can be reached there without any loss?? And also is there any method to send data in such a way

Q – 30 Suppose If you are given the IP address can u tell how many computers can be connected?What do you look at?

Ans- For Example in Class AIf IP address is 1.0.0.1 then Network bits is 8 bits and hosts bits are 24bits by calculating by formula 2n-2 (2power)Their fore for 1.0.0.1 the no computers can be connected 1,67,77,214

Q – 31 Tell me what is the default subnet mask for an ipv6 address?

Ans- A default subnet mask 255.0.0.0 for Class A,
255.255.0.0 for class B,
255.255.255.0 for Class C.

Q – 32 Explain what is system recovery and system failure?

Ans- System recovery is a process of an overall plan for system recovery so that we are prepared if the system fails. System recovery is a tow part system,including system recovery backup and system recovery restore.The SR Wizard, located in Backup, does the backup portion.

The wizard backs up the system state, system services, and all the disks that are associated with the operating system components.T he restore portion restores all the disk signatures, volumes, and partitions on (at a minimum) the disks that is need to start the computer.

A system failure will cause the system to freeze, reboot, or stop functioning altogether.System failure can occur because of a hardware failure or a severe software issue, example, when a hard disk drive fails, it will prevent the computer from being able to boot.When a system fail occurs we use system recovery to recover the system back to its condition.

Q – 33 What is the netted IP in Computer Networks?

Ans- Using a single IP address and locally splitting it up so that this single network IP address can actually be used on several interconnected local networks is known as netted IP.

Q – 34 What is IGP (Interior Gateway Protocol) in Computer Networks?

Ans- Within an autonomous system the interior gateway protocol (IGP) is used to exchange routing information.

There are two types of IGP
1.Distance-vector routing protocol
2.Link-state routing protocol.

Q – 35 Explain what services does the internet layer provide?

Ans- The internet layer packs data into data packets known as IP datagrams, which contain source and destination address information that is used to forward the datagrams between hosts and across networks. The Internet layer is also responsible for routing of IP datagrams.

Its job is to allow the host to insert packets to the internet,when data is sent, each layer treats all the information it receives as data and adds control information to the front of that data. This control information is called a header, and the addition of a header is called encapsulation. When data is received, the opposite procedure takes place as each layer removes its header before passing the data to the layer above.

The protocols include IP (Internet Protocol), ICMP (Internet Control Message Protocol),ARP (Address Resolution Protocol) and RARP (Reverse Address Resolution Protocol)

Q – 36 Explain what are headers and trailers? How are they added and removed?

Ans- Headers and trailers are the concepts of OSI model.
Headers are information structures which identifies the information that follows, such as a block of bytes in communication.
Trailer is the information which occupies several bytes at the end of the block of the data being transmitted.They contain error-checking data which is useful for confirming the accuracy and status of the transmission.

During communication of data the sender appends the header and passes it to the lower layer while the receiver removes header and passes it to upper layer. Headers are added at layer 6,5,4,3 & 2 while Trailer is added at layer 2.

Q – 37 What is Beaconing in Computer Networks?

Ans- Beaconing is a process which allows the network to render their network problems by them-selfToken ring and FDDI(Fibre Distributed Data Interface) networks make use of this process.

It is also a signalling error condition in wireless/LAN networks,during a failure the packets are transmitted as beacons,this beacon identifies the neighboring transmission which is active and helps in generation of an auto reconfiguration,hence the node which come under failure domain, automatically initiate a diagnostic measure and try to bypass the failure.

Q – 38 The network address made available to the transport layer should use a uniform numbering plan

1. In a session
2. In a LAN
3. In a WAN
4. across LAN and WAN

Ans- Across LANs and WANs.

Q – 39 What is virtual channel in Computer Networks?

Ans- A virtual channel defines a single point to point connection, identified by its virtual channel identifier.An individual channel can be uniquely identified by its virtual channel and virtual path number. The insertion of VCs enables to implement policies for allocating the physical channel bandwidth, which enables to support quality of service in applications.

Q – 40 Tell me what is terminal emulation, in which layer it comes?

Ans- Terminal emulation is the ability to make one computer terminal appear like some other terminal.

Terminal emulation is used to give the users the ability to log on and get direct access to legacy programs in a mainframe operating system.The emulation program runs like any other workstation application as a separate program task.

Terminal emulation comes in the application layer.

Q – 41 Explain what is anonymous FTP and why would you use it?

Ans- Anonymous FTP enables users to connect to a host without using a valid login and password. Usually, anonymous FTP uses a login called anonymous or guest, with the password usually requesting the user’s ID for tracking purposes only. Anonymous FTP is used to enable a large number of users to access files on the host without having to go to the trouble of setting up logins for them all. Anonymous FTP systems usually have strict controls over the areas an anonymous user can access.

Q – 42 What is the function of Transmission Control Block?

Ans- A TCB is a complex data structure that contains a considerable amount of information about each connection.

Q – 43 What is the difference between an unspecified passive open and a fully specified passive open?

Ans- An unspecified passive open has the server waiting for a connection request from a client. A fully specified passive open has the server waiting for a connection from a specific client.

Q – 44 What is a pseudo tty in Computer Networks?

Ans- A pseudo tty or false terminal enables external machines to connect through Telnet or rlogin. Without a pseudo tty, no connection can take place.

Q – 45 Tell me what is the difference between interior and exterior neighbor gateways?

Ans- Interior gateways connect LANs of one organization, whereas exterior gateways connect the organization to the outside world.

Q – 46 Explain what does the Mount protocol do?

Ans- The Mount protocol returns a file handle and the name of the file system in which a requested file resides. The message is sent to the client from the server after reception of a client’s request.

Q – 47 What advantage does REX offer other similar utilities?

Ans- Please share your answers.

Q – 48 What is piggy backing in Computer Networks?

Ans- Piggybacking is gaining access to restricted communication channel by using session that another user has already established. Piggybacking can be defeated by logging off before leaving a workstation or terminal or by initiating a protected mode, such as via a screensaver, that requires re-authentication before access can be resumed.

Q – 49 Suppose you are given only the IP address of the switch but not the port number. How will you read that switch?

Ans- A switch can have an Ip address for telnetting purpose.So, if you telnet to the switch, and if you have no password on Telnet you can access the switch (provided that there is no privileged mode password set) and then ‘Show Run’ , you can read the running configuration.

Q – 50 There are four routers and 4 switches and 40 computers in an office. How will you connect each devices and configure those devices?

Ans- This is using different network build purpose, so connect first router to first switch and connect 10 nodes with first switch, this is one network ex:192.168.1.0 networkand connect second router to second switch with 10 nodes this is another network ex:192.168.2.0 network the same method third router, fourth router ,third switch and fourth switch ex:192.168.3.0 network and 192.168.4.0 network now u connect all networks in one segment thats all.

Q – 51 which protocol is used for retrieving mails?

Ans- POP3 and IMAP4 are used to retrieve mails.IMAP4 stores a copy of message on the server whereas POP3 does not.

Q – 52 Explain benefits of VPN? Difference between L2TP and PPTP Protocols?

Ans- A Virtual Private Network ( VPN) delivers private network services over a public infrastructure. An IP VPN is a partitioned private network constructed over a shared IP-based backbone that utilizes technologies to ensure privacy of data. BenefitsIntranet ,Cost Effectiveness ,Security ,Flexibility,Reliability

Q – 53 Explain how Gateway is different from Routers?

Ans- Gateway is nothing but the final point that the data crosses finally in a network, it is mostly used for user authentication which router cannot provide. Gateways can provide authentication to anonymous users, it is used when u have only one single network. It is less costly. Whereas router is used for routing between different networks, providing routing tables and deciding best path for the data to travel. It is used when you have more than one networks. It is more costly.

Q – 54 How to configure two DHCP Servers using 2 swithces with 1 DSL. Keep in mind we cannot use any other additional equipment?

Ans- You configure what is known as Network Address Translation (NAT) on the router. This then translates the IP address of the server, which is likely to be a 10.x.x.x or 192.168.x.x address, to be the IP address it gets from your service provider. It keeps track of which server, and where it is going, so it can use the same ‘real’ IP address on the Internet for both of them.

Q – 55 How to use VPN to connect branch office to the other office?

Ans- By using a point-to-point protocol, that allows the branch office router act as a PPP initiator to the peer PPP router at the main office. Now, for security purpose, the PPP protocol packets can be tunneled using a tunnelling protocl like IPSec (tunnel mode) or L2TP etc.

Q – 56 Windows crashed because NTLDR File is missing. How will you restore this file (Without using Safe Mode Option)?

Ans- NTLDR is missingPress CTRL+ALT+DEL to restart. This problem may occur if the basic input/output system (BIOS) on your computer is outdated, or if one or more of the following Windows boot files are missing or damaged: NtldrNtdetect.comBoot.ini To resolve this issue, verify that the BIOS on your computer is current, as appropriate to your situation,u can solve it by repair this folder in the first repair in Win XP if u know name of his folder ..if u dont know u can repair all files …

Q – 57 What is difference between layer 2 and layer 3 switch?

How much bandwidth support by V.35 and RS 232 cable? What is difference between V.35 and RS 232 Cable?

Ans- Layer 2 switch forward or filter frames, layer 3 switch (router) use logical addressing and provide packet switching. Router also provide packet filtering by using acess list and when connect two or more network together and use logical addressing (IP). Besides, router use routing table to make path selection and forward packet to remote network.

Q – 58 Explain what is point-to-point protocol?

Ans- In networking, the Point-to-Point Protocol is commonly used to establish a direct connection between two nodes. Its primary use has been to connect computers using a phone line, though it is also occasionally used over broadband connections.

Q – 59 Explain what is the difference between collision domain and broadcast domain?

Ans- Broadcast Domain: A set of all devices that recieve broadcast frames originating from any device within the set. Broadcast domains are typically bounded by routers (or, in a switched network, by VLANs) because routers do not forward broadcast frames.

Collision Domain: In Ethernet, the network area within which frames that have collided are propagated. Repeaters and Hubs prpagate collisions, LAN switches and bridges do not.

Q – 60 Explain what is Private IP?

Ans- The address which can’t be routed through public (internet) are private ip addressesand it is scheam of saving public addressex:in class A range is10.0.0.0 to 10.255.255.255

Q – 61 Explain what is ipv6? How many octects is it?

Ans- IPv6 is basically the response to the fact that the world is/was running out of public ip addresses. The best example of stupidity leading to the problem is universities handing out public IP address to students and facility on their networks. A corporation would be insane to hand out public ip addresses to staff members.IPv6 default subnet is 255.255.255.255.0Ipv6 has 5 octets – 255.255.255.255.0Ipv4 has 4 octets – 255.255.255.0Personal OpinionIpv6 is not failure as such. I’m sure it’s implemented somewhere, but I’ve not seen it.

The solution to running out of IP addresses is better management of IPv4 addresses. Hardware/IOS manufactures often use 10.0.0.0 (called a ’10’ network) in examples of how to configure their devices. The students then return to their networks and implement their text book learning’s in their networks. BIG MISTAKE! Then these students wonder why things are all messed up on their networks. You should Class ‘C’ addressing on your private, smaller networks. It’ll work out much better for you.

Q – 62 Explain what is Active Directory? How does it work?

Ans- In windows 2000 and 2003 environment ads is a power full sercice ,active directory mainly used for maintaing and promotion of entire company into centralized network administration .it means domine evironmnet

Q – 63 What is layer-3 switch in Computer Networks?

Ans- A layer 2 switch provides connectivity but doesn’t act upon the packets at all. These switches are often found in small offices, your home or on the very edge of a LAN to provide Internet or client/server communication. A layer 3 switch provides connectivity but can also provide routing, access lists, QOS and even security. These are usually much more expensive switches with IOS’s installed.

They are best used in video conferencing to keep video packets together through QOS. For video, your cable should run directly to the layer 3 switch and not pass through any other lessor switch to avoid tiling, delays and other issues that affect video quality.

Q – 64 Tell me what are the two types of transmission technology available?

(i) Broadcast and(ii) point-to-point

Ans- There are basically 2 types of transmission technologies1.Broadband :In this type .Every host sends the packet/message to all the host.the message has a source address and a destination address. destination address helps the host to identify whether the message is indeed for them or somebody elsethe source address allows them to identify from whom the message has come.2.Point to Point :In this type of technology there are multiple connections (transmission lines) between 2 hosts. so the the packet can take different routes if a particular route is congested.

Q – 65 Explain difference between the communication and transmission. Transmission is a physical movement of information and concern issues like bit polarity, synchronization, clock etc. Communication means the meaning full exchange of information between two communication media?

Ans- Difference between the communication and transmission. Transmission is a physical movement of information and concern issues like bit polarity, synchronisation, clock etc. Communication means the meaning full exchange of information between two communication media.

Q – 66 What is the difference between TCP/IP host name and netBIOS host name?

Ans- NetBIOs name is system Name it is only 15 character long and resolve by NetBios protocal.TCP/IP Name is full system name. it is 65 characters long and resolved by windows scoket protocal.

Q – 67 What is Recovery Console?

Ans- Recovery Console for example if you install a software in exsisting windows and due to the software if the system have some problem you can choose Recovery console at Start -programs-accessories-system tools-Recovery consoleenter it and you can see the Timetable of Recovery console select the previous date of which you installed and select Restore. it can have a back up of Registery Files

Q – 68 Explain what is autonomous system?

Ans- Autonomous system has been assigned a number which differentiates it from other autonomous systems to communicate. there is BGP working at to communicate with other AS

Q – 69 Tell me whats are the core differences Between TCP and UDP?

Ans- In transport layer two protocols are working TCP , transmission control protocol and UDP , user datagram protocol , TCP is also know as reliable protocol , means it is using handshake process , where client requtest to server then establish the connection and then transfer the packet then terminates it. In UDP , no relaibilty but packets are safe. when long RTO is there that time packtes use to UDP.

Q – 70 Explain what is the advantage and disadvantage of local area networks?

Ans- Please share your answers.

Q – 71 What is EGP (Exterior Gateway Protocol) in Computer Networks?

Ans- It is the protocol the routers in neighboring autonomous systems use to identify the set of networks that can be reached within or via each autonomous system.

Q – 72 Explain how data can be effectively communicated from the transmitter to the receiver?

Ans- Data can be effectivily transmmited through E1 leased line.But E1 leased line is very Costly. so by using VPN ( Virtual Private Network) We send data very effectivily in less cost than E1 leased line.Vpn also need internet connection to send data from source to server.

Q – 74 Explain what do you exactly mean by end to end delivery of packets? (i.e n/w layer and transport layer)

Ans- actually end to end delivery of packets is done by network layer. Network layer is responsible for the packets to be delivered with reliability for every link i.e for every routers it come across its path.so packet is delivered with reliability from source to destination. where as transport layer is reaponsible for process to process reliability.it gets the packets from network layer demutiplex it to sen it to corresponding application (FTP,Email,…) depending upon the portnumber that is specified.

Q – 75 What MAU in Computer Networks?

Ans- Short for Multistation Access Unit (also abbreviated as MSAU), a token-ring network device that physically connects network computers in a star topology while retaining the logical ring structure. One of the problems with the token-ring topology is that a single non-operating node can break the ring. The MAU solves this problem because it has the ability to short out non-operating nodes and maintain the ring structure. A MAU is a special type of hub.

Q – 76 BOOTP helps a diskless workstation boot. How does it get a message to the network looking for its IP address and the location of its operating system boot files?

Ans- BOOTP sends a UDP message with a subnetwork broadcast address and waits for a reply from a server that gives it the IP address. The same message might contain the name of the machine that has the boot files on it. If the boot image location is not specified, the workstation sends another UDP message to query the server.

Q – 77 Explain what the difference between DNS and WINS?

Ans- DNS- Domain Name Server or Services.WINS- Windows Internet Name Service.DNS is resolve the web site name to IP address or you can say.In WINS used a file name those is LMhost, this file in the System32, and when we put the websit name and its IP address, then it resolve the particular IP address those insert in the LMhost file.

Q – 78 What is SIMM?

Ans- SIMM is used to store a single row of DRAM,EDo or BEDO chips where the module is soldered onto a PCB.

Q – 80 What is a Management Information Base (MIB) in Computer Networks?

Ans- This term comes from the OSI Network management model. It is a kind of virtual database used to manage the devices in a network. It consists of record the of network entities( e.g. routers,switches) in form of objects. The database is hierarchical (tree structured) and entries are addressed through object identifiers.

Q – 81 The network address made available to the transport layer should use a uniform numbering plan

1. In a session 2. In a LAN
3. In a WAN 4. across LAN and WAN

Ans- The network address made available to the transport layer should use a uniform numbering plan In a session

Q – 82 Piggybacking Suggests

1. attaching a check bit to an outgoing data frame
2. attaching an acknowledge to an outgoing data frame
3. saving some memory space for the critical processes
4. securing the data frames before transporting

Ans- Piggybacking Suggestsattaching an acknowledge to an outgoing data frame

Q – 84 What is MAC address in Computer Networks?

Ans- Short for Media Access Control address, a hardware address that uniquely identifies each node of a network. In IEEE 802 networks, the Data Link Control (DLC) layer of the OSI Reference Model is divided into two sublayers: the Logical Link Control (LLC) layer and the Media Access Control (MAC) layer. The MAC layer interfaces directly with the network medium.

Consequently, each different type of network medium requires a different MAC layer. On networks that do not conform to the IEEE 802 standards but do conform to the OSI Reference Model, the node address is called the Data Link Control (DLC) address. See a breakdown of the seven OSI layers in the Quick Reference section of Webopedia.

Q – 87 What is the difference between routable and non- routable protocols?

Ans- Routable protocols can work with a router and can be used to build large networks. Non-Routable protocols are designed to work on small, local networks and cannot be used with a router

Q – 88 How to ping from one host to another in IPv6 without ARP?

Ans- By using the Neighbour Discovery Protocol (NDP)

Q – 89 Explain which protocol is used to communicate between client and ISP?

Ans- OSPF is used. Because it is considered to be the most efficient IGP(interior gateway protocol). BGP is more widely used as exterior gateway protocol(EGP).

Q – 90 Suppose you have been given 1 printer and 1 IP Address for installing it in a Networking Environment
How will you do it?

Ans- Just you go to the start menu -> setting -> printers and fax -> add a printer
-> local printer attached to this pc -> create the new port -> select the standard tcp/ip protocol
-> and enter the ip address and insert the printer CD for driver and install the printer drive.
The printer is now ready to use.

Q – 91 Explain what is the difference between .pst and .ost files used in outlook?

Ans- .pst files are all the emails (and files attatched to those emails), calendar, contacts, tasks, etc. stored locallyon your machine..pst are created when using Outlook to manage your email (Gmail, hotmail, yahoo, aol,etc.) they can also be created within an Exchange environment, however, Microsoft doesn’t recomment this due to the .pst being very unstable and if your pc were to crash you would loose all of your emails.

In an Exchange environment, using .pst removes the emails from the Exchange server and stores them locally..ost files are simply a copy of your mailbox that is stored on the Exchange server. Think of this as a type of email cache file. This leaves the emails on the server, but also stores a copy of emails since your last sync on the local machine.

Q – 92 Explain what is passive topology?

Ans- When the computers on the network simply listen and receive the signal, they are referred to as passive because they don’t amplify the signal in any way. Example for passive topology – linear bus.

Q – 93 What is cladding in Computer Networks?

Ans- Material placed on the exterior of wood frame and sash components to provide ease of maintenance. Common cladding materials include vinyl and extruded or roll-formed aluminum

Q – 94 Tell us why do we have a minimum and maximum cable length requirement?

Ans- The min and max cable length is required because the signals can travel effectively without loosing their strength to that extent you can increase the cable length apart from preferred by using the repeaters after the length so that the signals will be boosted again.

Q – 95 Explain what are the important topologies for networks?

Ans- BUS topology:

In this each computer is directly connected to primary network cable in a single line.

Advantages:

Inexpensive, easy to install, simple to understand, easy to extend.STAR topology:In this all computers are connected using a central hub.

Advantages:

Can be inexpensive, easy to install and reconfigure and easy to trouble shoot physical problems.

RING topology:

In this all computers are connected in loop.

Advantages:

All computers have equal access to network media, installation can be simple, and signal does not degrade as much as in other topologies because each computer regenerates it.

Q – 96 TCP is reliable in communication whereas IP is Non-reliable. Why it is integrated into one and given as TCP/IP protocol?

Ans- Reliability not achieved at lower layers shall be implemented at the higher layers and more importantly each Layer in TCP/IP protocol suite is responsible for some network operations. IP though unreliable it implements routing of network information across the nodes upto the destination. But TCP cannot do this it implements only the end-to-communication (i.e) the source and destination without taking care of the intermediate nodes across which the network information should pass through which is done by IP layer. Therefore IP is integrated with TCP.

Q – 97 What is attenuation in Computer Networks?

Ans- When we transmit any signal, the signal strength is degraded because of losses, interference, this is called attenuation of the signal. To reduce attenuation, repeaters are used to boost the signal strength.

Q – 98 What does negotiation mean when discussing network protocols?

Ans- The Difference Between Half and Full Duplex.”Duplex” simply means you’re able to send and receive data (most often the human voice) from the same device whether that be with your phone, 2-way radio, or PC.Half-duplex devices let you send and receive, but only one-way at a time.

If you’ve ever used a walkie-talkie, then you know what half-duplex conversations sound like. You have to push the TALK button to send your message. But as long as you are holding the TALK key, you can’t hear what anyone else is saying. You must release the button to receive.

Full duplex actually, full duplex is nothing new. In fact, you already know exactly what it sounds like. Your corded or cordless phones are full-duplex devices letting you and your caller speak simultaneously without any dropouts in either one of your voices.Half- and Full-Duplex ModeEach switch port can operate in either half-duplex or full-duplex mode.Half Duplex = send or receive dataFull Duplex = send and receive dataAutonegotiationThe switch supports the autonegotiation of both speed and duplex mode.

As a result, when the switch is connected to another network device that is capable of autonegotiation, the two devices communicate common speeds and duplex modes to each other. Then, the highest common capabilities for both devices become the operating modes. The switch has the following operating priorities:1. 100 Mbps, full-duplex mode2. 100 Mbps, half-duplex mode3. 10 Mbps, full-duplex mode4. 10 Mbps, half-duplex mode Note: Hub operates in Half Duplex Mode, whereas the switch operates in both Half and Full Duplex Mode.

Q – 99 Tell me what is VPN? Is RAS and VPN one and the same?How do I determine that My computer is part of correct network and is getting a Valid IP?

Ans- SD RAM:SDRAM is Single Data Rate meaning that SDRAM can accept one command and transfer one word of data per clock cycle. Typical speeds of SDRAM are 100 and 133 MHz.DDR SDRAM:DDR SDRAM transfers data twice per clock cycle, hence the name double data rate. DDR clock speeds range between 200 MHz (DDR-200) and 400 MHz (DDR-400).

DDR-200 transfers 1600 MB/s, while DDR-400 transfers 3200 MB/s.DDR2 SDRAM:DDR2 SDRAM is twice as fast as DDR which means twice as much data is carried to the module for each clock cycle. Also consumes less power as compared to the DDR memory.

Q – 100 Suppose a person would like to access a file on another computer (connected via LAN) while working with safe mode. What should he do?

Ans- In safemode itself he can use telnet to access file on the other system in the same LAN

Q – 101 Explain Data Transmission From Server to Server?

Ans- State the technical steps required for data transmission from server to server via a router and switch

Q – 102 What is VLAN and INTERVLAN? Why do we use these techniques?

Ans- VLAN(Virtual Local Area Network) is a logical grouping of network users and resources connected to administratively defined ports on a switch. VLAN’s break up broadcast domains in layer 2 switch network.Virtual LANs (VLANs) divide one physical network into multiple broadcast domains. But, VLAN-enabled switches cannot by themselves, forward traffic across VLAN boundaries. So you need to have routing between these VLANs which is called interVLAN routing. You can achieve this by using either a Layer 3 switch or a router.

Q – 103 Explain what is the function of a WAP gateway?

Ans- Implementation of the WAP stack Converting protocols Converting markup languages Compiling WMLScript programs Encoding WML into a binary bitstream Providing access control Caching Domain name resolution services (DNS) Security features

Q – 104 When two network layers are in communication with one another, these layers are known as?

a.) PDUs
b.) peer entiies
c.) PRAMs
d.) sockets

Ans- B.) Peer Entities
Q – 105 What is the process of OSI Model, when two computer communicate with each other?

Ans- OSI model could be big. I will explain it in TCP/IP model, which is used in modern computersThe TCP/IP model has the following Layers.ApplicationTransportNetworkData LinkPhysicalApplication:When 2 PCs want to communicate they often use an application to communicate. Applications are user interfacing and is in a format understandable by the user.

The application layer provides a user with various application services, which a user decides upon the communication. Lets just say PC A wants to send a word document to PC B. Word is an application that a user users at the application layerTransport:This layer multiplexes data.

The need for multiplexing, is that there could be many services that would want to communicate with different destinations. This layer in the TCP/IP model, uniquely identifies to the recieving device what application layer program the data sent is destined to.

Along with this this layer also provides a user with different reliabilty modes depending upon the protocol usedNetwork:This layer is responsible for logical addressing to identify the network where the reciveing station isData link:This layer is where the data gets another tag with the physical address of the device, to identify exactly what PC the data is destined to in the network identified by the network layer.

The physcial address often depends upon the technolgy that you are using (ethernet, token ring, frame relay, PPP etc).Also the data gets split in to series of bits of 0s and 1s and sent to the lower layerPhysical:This is the layer where the data in form of bits recieved from the data link layer gets transmitted in form of electrical signals to the destination