Networking Interview Questions

Computer Networks Interview Questions

What protocol is used by DNS name servers ?
DNS uses UDP for communication between servers. It is a better choice than TCP because of the improved speed a 

connectionless protocol offers. Of course, 

transmission reliability suffers with UDP.

What is the difference between interior and exterior neighbor gateways? 
Interior gateways connect LANs of one organization, whereas exterior gateways connect the organization to the outside 

world.

What is RIP (Routing Information Protocol)
It is a simple protocol used to exchange information between the routers.


What is OSPF ?
It is an Internet routing protocol that scales well, can route traffic along multiple paths, and uses knowledge of an 

Internet's topology to make accurate routing decisions.

What is Kerberos ?
It is an authentication service developed at the Massachusetts Institute of Technology. Kerberos uses encryption to 

prevent intruders from discovering passwords and 

gaining unauthorized access to files.

What is Mail Gateway? 

It is a system that performs a protocol translation between different electronic mail delivery protocols.

Why should you care about the OSI Reference Model

It provides a framework for discussing network operations and design.

What is the difference between routable and non- routable protocols

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.

What is the difference between TFTP and FTP application layer protocols ? (Asked in IBM Interview)

The Trivial File Transfer Protocol (TFTP) allows a local host to obtain files from a remote host but does not provide reliability or security. It uses the fundamental packet delivery services offered by UDP.

The File Transfer Protocol (FTP) is the standard mechanism provided by TCP / IP for copying a file from one host to another. It uses the services offered by TCP and so is reliable and secure. It establishes

What is difference between ARP and RARP ?
The address resolution protocol (ARP) is used to associate the 32 bit IP address with the 48 bit physical address, used 

by a host or a router to find the physical address of 

another host on its network by sending a ARP query packet that includes the IP address of the receiver.

The reverse address resolution protocol (RARP) allows a host to discover its Internet address when it knows only its 

physical address.

What is ICMP ?
ICMP is Internet Control Message Protocol, a network layer protocol of the TCP/IP suite used by hosts and gateways to 

send notification of datagram problems back to the 

sender. It uses the echo test / reply to test whether a destination is reachable and responding. It also handles both 

control and error messages.

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.

What is MAC address ?

The address for a device as it is identified at the Media Access Control (MAC) layer in the network architecture. MAC 

address is usually stored in ROM on the network 

adapter card and is unique.

What is RAID
A method for providing fault tolerance by using multiple hard disk drives.


What is subnet ?
A generic term for section of a large networks usually separated by a bridge or router.


What is difference between baseband and broadband transmission
In a baseband transmission, the entire bandwidth of the cable is consumed by a single signal. In broadband 

transmission, signals are sent on multiple frequencies, allowing 

multiple signals to be sent simultaneously.

What are the possible ways of data exchange
(i) Simplex (ii) Half-duplex (iii) Full-duplex.

What is point-to-point protocol ?

A communications protocol used to connect computers to remote networking services including Internet service 

providers.