Top Computer Network Interview Questions

This article includes some of the top network interview questions with answers that can benefit candidates attending a job interview on Networking. We have tried our best to include all the relevant and most-asked questions and explain them in lucid language so everyone can understand them.

What is Network?

A network of multiple computers or sets of devices connected to share resources, allowing electronic communication and exchanging files. These computers can be linked through.cables, the internet, satellites, telephone lines, radio waves, or infrared light beams.

What is a Node?

Node is a network component used for sending or receiving electronic communication.

When you connect two or more computers, you do that through optical fiber or other cables. The point that establishes a connection is known as a node. It can also be a device connected to a network. For example, if you have two computers, one printer, and a server connected, there are four network nodes.

What Is a Network Protocol?

A network protocol is a set of rules determining how data are transmitted between devices within the same network. It allows devices to communicate with each other without changing the internal process, design, or structure.

What are the different types of Network Protocols?

There are Three Types of Network Protocols

  • Network communication protocols such as TCP/IP and HTTP.

  • Network management protocols such as ICMP and SNMP.

  • Network security protocols like HTPPS, SSL, and SFTP.

How to Check the Network Reliability?

The reliability of a network is measured through three factors: downtime, failure frequency, and catastrophe.

Downtime is the time it requires for a network to recover.

Failure frequency is the number of times a network fails to work as intended, and catastrophe refers to when the network is attacked by unexpected events such as earthquakes, fire, flood, etc.

What can affect the security of the network?

The security of a network can be affected by two factors: unauthorized access and viruses.

What can affect the performance of a network?

The network performance can be affected by the following

  • Number of users

  • Types of transmission medium used

  • Hardware and software

What is the TCP protocol?

TCP or TCP/IP (Transmission Control Protocol/Internet Protocol) is a set of rules that decides the connectivity between a computer and the internet. It also determines how data is transmitted over the network.

It works by creating a virtual network when a network is connected to more than one computer. It helps establish a secure connection using the three-way handshake model.

What is the three-way handshake model?

Three ways handshake model or TCP 3-way handshake involves connecting a server to the client over the TCP/IP network.

The three-way handshake model is established in three steps

Step 1:SYN (Synchronize Sequence Number)

The client sends a segment with SYN informing the server that they are about to start a communication.

Step 2:SYN+ACK (Acknowledgement)

The server responds to the client request with the SYN-ACK signal bits set. ACK is the response of the segment the server received, while SYN signifies the sequence number the server will start the feature.

Step 3:ACK

The client acknowledges the server’s response and establishes a connection in this part.

What is the UDP protocol?

Short for User Datagram Protocol, UDP is used for multicasting and broadcasting. The process is the same as TCP/IP protocol, except it doesn’t use any hand-shaking method, making it less reliable.

5 Differences between TCP and UDP



It is a connection-based protocol.

It doesn’t require any connection.

Transmission is slower.

Transmission is faster.

You can preserve and rearrange the order of the packet

Packet orders are independent of each other and are fixed.

Error checking mechanism makes it more reliable.

There is no error-checking mechanism.

It uses a three-way handshake model.

No handshake model is used.

What is the OSI Reference Model?

The OSI (open system interconnections) is a network architecture model that complies with ISO standards. It connects various systems (that are open for communication) with other systems.

What are the Seven Different Layers of the OSI Reference Model?

Following are the Seven Layers of the OSI Reference Model

Application, presentation, and session layers that collectively called the software layers.

The transport layer is the center of the OSI.

Network, data link, and the physical layer known as the Hardware layers.

What is the DHCP Protocol?

DHCP or Dynamic Host Configuration Protocol is an application layer protocol used for autoconfiguring devices on IP networks, using TCP and UDP-based protocols.

What is the ARP protocol?

Address Resolution Protocol (ARP) involves the process of mapping a dynamic IP address to a physical machine address (MAC) in the local area network (LAN).

Differentiate the MAC address from the IP address

MAC Address

IP Address

It is known as the Media Access Control Address.

It is known as the Internet Protocol Address.

It is a physical address containing a six or 8-byte hexadecimal number.

It is a logical address containing 4(IPv4) or17(IPv6) byte addresses.

It is used to identify the device.

It is used to identify the device connectivity over a network.

It operates at the data link layer.

It operates at the Network layer.

It comes embedded with NIC.

It is retrieved via the network.

What is a Subnet?

A subnet comprises a network within a network which is conducted through the subnetting process. It allows you to divide a network into subnets, get a higher routing efficiency, and improve network security.

What is the Firewall?

The firewall is the network security system that monitors incoming and outgoing traffic. It can block traffic if it doesn’t comply with the firewall security policies by acting as a wall between the internet and networking devices. A firewall can be software, a hardware device, or both.

What are the different types of Networks?

Different types of the network include PAN (Personal Area Network), LAN (Local Area Network), MAN (Metropolitan Area Network), WAN (Wide Area Network), and GAN (Global Area Network).

Explain LAN (Local Area Network)

LAN is a widely used network to connect computers and electronic devices, allowing them to share resources and exchange information.

Two LAN networks are available − Wireless LAN (no wires involved, such as wi-fi) and wired LAN (involves LAN cable).

Tell us something about VPN (Virtual Private Network)

VPN is a private and virtual WAN (vast area network) that allows you to create a secure tunnel or a protective network between two networks for using the internet. It will enable you to connect remotely to offices in different geographical locations. It keeps your information secured against potential threats by encrypting the internet traffic and disguising your IP address and other online identities.


We hope this article covers all the crucial network interview questions. Meanwhile, you will find a lot of other questions on the internet that you can search for extra knowledge. We wish you all the best for your Networking interview.