Networking Interview Questions and Answers

Networking Interview Questions

These Networking questions have been designed for various interviews, competitive exams and entrance tests. We have covered questions on both basic and advanced concepts which will help you improve your skills to face interview questions on Networking.

Who are these Networking interview questions designed for?

All the network engineers, security analysts, network security engineers, cyber security engineers, network administrators, network specialists etc. will find these questions extremely useful. All freshers, BCA, BE, BTech, MCA and college students wanting to make a career in Networking will be highly benefited by these questions.

Networking interview questions topics

This section covers Networking topics like - Domain , Workgroup, Network Hub, Switch, Router, DNS Server, proxy server, HTTP and HTTPS, SSL, gateway, Network topologies, baseband transmission, broadband transmission etc.

1. What is the difference between a Domain and a Workgroup?

Domain and Workgroup represent different methods for organizing computers in networks. All Windows Computers on a network must be part of a Workgroup or a Domain.

The main differences are as follows:

i. In a workgroup, no computer has control over another computer. All of them are peers. In a domain, one or more computers are servers. These servers are used by the Network Engineers to control the security and permissions for all the computers in the domain.

ii. Workgroups don't have server and controller. All computers have the same amount of control. In a Domain, there is a domain controller that checks for authentication and authorization of users on the network. Only authorized users can connect to the server and access resources which make a domain safer and secured.

iii. In a Workgroup, you must have an account on that computer to use it. On the contrary, the user account is maintained on a server in a domain. So, you can log on to any computer on the domain without needing an account on that computer.

iv. Workgroups are good for smaller networks with no more than ten to twenty computers. There is no limitation on the number of computers in a domain

v. In a Workgroup, all computers must be on the same local network whereas the computers can be on different local networks in a domain environment.

Video : Network Engineer Interview Questions and Answers - For Freshers and Experienced Candidates

2. Difference between a Network Hub, Switch and Router.

A network hub, switch, and router are the devices that work to connect one computer to another computer.    

A network hub connects multiple computers together in a private network. A hub broadcasts data packet to all other connected devices when it receives packet of data from a connected device. Consequently, network bandwidth is split between all of the connected computers and makes connection slower. This is the reason why network hubs are rarely used.

Like a hub, a switch also connects computers to each other. But it makes the network more efficient because it doesn't broadcast data packet to all other connected devices. Instead, it sends the data packets to intended computer only and for this reason, the switches are preferred over a hub.

A router is a device that joins networks together and routes data packets between them.

3. What is a DNS Server? Why is it used?

A DNS Server may be referred by other names such as a name server or nameserver, and a domain name system server. It is the phonebook of the internet which contains a database of public IP addresses and their associated hostnames or domain names. We interact online using domain names like but Web browsers interact through Internet Protocol (IP) addresses. So, when we access information using domain name, a DNS translates or resolves that domain name to IP addresses so browsers can load Internet resources.

4. What are different ways of securing a computer network?

There are several ways to make a highly secured network.

Some of them are enlisted below:

i) Make sure firewalls are setup and configured properly to control incoming and outgoing network traffic and prevent unauthorized access to computers and networks.

ii) Install reliable and updated anti-virus program on all computers. Also, perform regular updates of your anti-virus software.

iii) Ensure authenticating all users before allowing them to access the network.

iv) Use VPN (Virtual Private Network) if employees are allowed access to private network from remote networks. VPN uses encryption and multi-factor authentication to provide greater security.

v) Keep a wireless Local Area Network (WLAN) separate from the main company network.

5. What is proxy server and how does it protect computer networks?

Proxy server is the server which is placed between the client and the internet. It makes a network virtually invisible to external users.

Proxy server protects computer networks in following ways:

i. Obscure client IP - Proxy server hides the real IP address of a user in the network, instead it provides its own logical IP address to the public network. This way it prevents unauthorized users to detect the real IP address of your computer and hack it.

ii. Block Sites - Proxy server allows blocking unwanted websites.

iii. Log Activity - Proxy server allows a network administrator to monitor users in the network and know his activities on the internet.

iv. Improve Performance - Proxy server allows caching of recent and frequent webpage/website requests on the server and share them to other users of the network. Thus, it delivers frequently used content faster and uses lesser bandwidth.  

v. Access control - We can also filter the request using Proxy server. For example, a network administrator can set a rule where selected users can access social media websites while others can't.

6. What are the different types of email servers and which ports do they use?

We have two types of email servers :

Incoming Mail Server (POP3 port 110, IMAP Port 143, HTTP Port 30)

Outgoing Mail Server (SMTP port 25)

7. Explain the difference between HTTP and HTTPS?

HTTP stands for HyperText Transfer Protocol and is used by majority of websites as means for transmitting website data using TCP port 80.

HTTPS is a secure version of HTTP that allows for identity verification and low level encryption using TCP port 443

8. How would you determine connection path between local host and a server?

You can determine connection path between your computers to the destination server using Traceroute command.

It is a network diagnostic tool used to diagnose network routing issues. It lists all the routers the data packet passes through until it reaches its destination and also measures any transit delays.

9. What is the use of a default gateway?

Default gateway bridges the gap between local and external network. It is a node/IP router in a local network through which a networked computer can communicate with external network or Internet.

10. What advantages do fiber optics have over other media?

Fiber optic is less susceptible to electrical interference. It supports higher bandwidth and signal degrading is also very minimal over long distances.

11. What are the important topologies for network?

i.) Bus topology - All computers are connected in series along a linear path.

ii.) Star topology - All computers are connected to a central computer, called a hub or switch.

iii.) Ring topology - All computers are directly connected to the next computer in a circular fashion.

iv.) Mess topology - Every node has a connection to every other node in the network.

12. What are the duties of Data Link Layer?

The data link layer is the second layer in the OSI Model.

The main functions of the data link layer are:

i.) It deals with transmission errors
ii.) It regulates the flow of data
iii.) It provides a well-defined interface to the network layer.