Top 37 Networking Interview Questions

Top 37 Networking Interview Questions: Here are the top interview questions of Networking. Be prepared for the interview. You can download the entire questions in a pdf format. so guys All the best for your interview.

1) What is a Network?

A network is a set of devices connected to each other using a physical transmission medium.

Example: A Computer Network is a group of computers connected with each other to communicate and share information and resources like hardware, data, and software across each other.

In a network, nodes are used to connect two or more networks.

2) What is a Node?

Two or more computers are connected directly by an optical fiber or any other cable. A node is a point where a connection established. It is a network component which is used to send, receive and forward the electronic information.

A device connected to a network is also termed as Node. Let’s consider that in a network there are 2 computers, 2 printers, and a server are connected, then we can say that there are five nodes on the network.

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3) What is Network Topology?

Top 37 Networking Interview Questions Network Topology is a physical layout of the computer network and it defines how the computers, devices, cables, etc are connected to each other.

4) What are Routers?

The router is a network device which connects two or more network segments. The router is used to transfer information from the source to the destination.

Routers send the information in terms of data packets and when these data packets are forwarded from one router to another router then the router reads the network address in the packets and identifies the destination network.

5) What is OSI reference model?

Open System Interconnection, the name itself suggest that it is a reference model which defines how applications can communicate with each other over a networking system.

It also helps to understand the relationship between networks and defines the process of communication in a network.

6) Which are the different factors that affect the reliability of a network?

The following factors affect the reliability of a network:

  • Frequency of failure
  • Recovery time of a network after a failure

7) Which are the different factors that affect the performance of a network?

The following factors affect the performance of a network:

  • A large number of users
  • Transmission medium types
  • Hardware
  • Software

8) What makes a network effective and efficient?

There are mainly two criteria which make a network effective and efficient:

  • Performance:: performance can be measured in many ways like transmit time and response time.
  • Reliability: reliability is measured by the frequency of failure.
  • Robustness: robustness specifies the quality or condition of being strong and in good condition.
  • Security: It specifies how to protect data from unauthorized access and viruses.

9) What is bandwidth?

Top 37 Networking Interview Questions Every signal has a limit of upper range frequency and lower range frequency. The range of limit of a network between its upper and lower frequency is called bandwidth.


10) What is a node and link?

A network is a connection setup of two or more computers directly connected by some physical mediums like optical fiber or coaxial cable. This physical medium of connection is known as a link, and the computers that it is connected are known as nodes.

11) What is data encapsulation?

Data encapsulation is the process of breaking down information into smaller manageable chunks before it is transmitted across the network. It is also in this process that the source and destination addresses are attached into the headers, along with parity checks.

12) Describe Network Topology

Network Topology refers to the layout of a computer network. It shows how devices and cables are physically laid out, as well as how they connect to one another.

13) What is VPN?

VPN means Virtual Private Network, a technology that allows a secure tunnel to be created across a network such as the Internet. For example, VPNs allow you to establish a secure dial-up connection to a remote server.

14) Briefly describe NAT.

NAT is Network Address Translation. This is a protocol that provides a way for multiple computers on a common network to share single connection to the Internet.

15) What is the job of the Network Layer under the OSI reference model?

The Network layer is responsible for data routing, packet switching and control of network congestion. Routers operate under this layer.

16) What are IP classes and how can you identify the IP class of given a IP address?

An IP address has 4 sets (octets) of numbers each with a value up to 255.

For Example, the range of the home or commercial connection started primarily between 190 x or 10 x. IP classes are differentiated based on the number of hosts it supports on a single network. If IP classes support more networks then very few IP addresses are available for each network.

There are three types of IP classes and are based on the first octet of IP addresses which are classified as Class A, B or C. If the first octet begins with 0 bit then it is of type Class A.

Class A type has a range up to 127.x.x.x (except 127.0.0.1). If it starts with bits 10 then it belongs to Class B. Class B having a range from 128.x to 191.x.  IP class belongs to Class C if octet starts with bits 110. Class C has a range from 192.x to 223.x.

17) What is meant by 127.0.0.1 and local host?

IP address 127.0.0.1, is reserved for loopback or local host connections. These networks are usually reserved for the biggest customers or some of the original members of the Internet. To identify any connection issue, the initial step is to ping the server and check if it is responding.

If there is no response from the server then there are various causes like the network is down or the cable needs to be replaced or network card is not in good condition. 127.0.0.1 is a loopback connection on the Network Interface Card (NIC) and if you are able to ping this server successfully, then it means that the hardware is in a good shape and condition.

127.0.0.1 and local host are the same things in most of the computer network functioning.

18) What is NIC?

Top 37 Networking Interview Questions NIC stands for Network Interface Card. It is also known as Network Adapter or Ethernet Card. It is in the form of add-in card and is installed in a computer so that the computer can be connected to a network.

Each NIC has a MAC address which helps in identifying the computer on a network.

19) What is Data Encapsulation?

In a computer network, to enable data transmission from one computer to another, the network devices send messages in the form of packets. These packets are then added with the IP header by OSI reference model layer.

The Data Link Layer encapsulates each packet in a frame which contains the hardware address of the source and the destination computer. If a destination computer is on the remote network then the frames are routed through a gateway or router to the destination computer.

20) What is the difference between Internet, Intranet, and Extranet?

The terminologies Internet, Intranet, and Extranet are used to define how the applications in the network can be accessed. They use similar TCP/IP technology but differ in terms of access levels for each user inside the network and outside the network.

Internet: Applications are accessed by anyone from any location using the web.

Intranet: It allows limited access to the users in the same organization.

Extranet: External users are allowed or provided with access to use the network application of the organization.

21) What is private IP address?

Top 37 Networking Interview Questions There are three ranges of IP addresses that have been reserved for IP addresses. They are not valid for use on the internet. If you want to access internet on these private IPs, you must have to use proxy server or NAT server.


22) What is public IP address?

A public IP address is an address taken by the Internet Service Provider which facilitates you to communication on the internet.


23) What is APIPA?

APIPA is an acronym stands for Automatic Private IP Addressing. This feature is generally found in Microsoft operating system.


24) What is the full form of ADS?

  • ADS stands for Active Directory Structure.
  • ADS is a microsoft technology used to manage the computers and other devices.
  • ADS allows the network administrators to manage the domains, users and objects within the network.
  • ADS consists of three main tiers:
    • Domain: Users that use the same database will be grouped into a single domain.
    • Tree: Multiple domains can be grouped into a single tree.
    • Forest: Multiple trees can be grouped into a single forest.

25) What is RAID?

RAID is a method to provide Fault Tolerance by using multiple Hard Disc Drives.

26) What does 10Base-T mean?

The 10 refers to the data transfer rate, in this case is 10Mbps. The word Base refers to base band, as oppose to broad band. T means twisted pair, which is the cable used for that network.

27) What is a private IP address?

Private IP addresses are assigned for use on intranets. These addresses are used for internal networks and are not routable on external public networks. These ensures that no conflicts are present among internal networks while at the same time the same range of private IP addresses are reusable for multiple intranets since they do not “see” each other.

28) What is NOS?

NOS, or Network Operating System, is specialized software whose main task is to provide network connectivity to a computer in order for it to be able to communicate with other computers and connected devices.

29) What is DoS?

DoS, or Denial-of-Service attack, is an attempt to prevent users from being able to access the internet or any other network services. Such attacks may come in different forms and are done by a group of perpetuators. One common method of doing this is to overload the system server so it cannot anymore process legitimate traffic and will be forced to reset.

30) What is OSI and what role does it play in computer networks?

OSI (Open Systems Interconnect) serves as a reference model for data communication. It is made up of 7 layers, with each layer defining a particular aspect on how network devices connect and communicate with one another. One layer may deal with the physical media used, while another layer dictates how data is actually transmitted across the network.

31) Explain the characteristics of networking?

The main characteristics of networking are mentioned below,

  • Topology: This deals with how the computers or nodes are arranged in the network. The computers are arranged physically or logically.
  • Protocols: Deals with the process how the computers communicate with one another.
  • Medium: This is nothing but the medium used by the computers for communication.

32) How many types of modes are used in data transferring through networks?

Data transferring modes in computer networks are of three types. They are listed below,

1) Simplex: Data transferring which takes place only in one direction is called Simplex. In Simplex mode, the data gets transferred either from sender to receiver or from receiver to sender.

Eg: Radio signal, the print signal given from computer to printer etc.

2) Half Duplex: Data transferring can happen in both directions but not at the same time. Alternatively, the data is sent and received.

Eg: Browsing through the internet, a user sends the request to the server and later the server processes the request and sends back the web page.

3) Full Duplex: Data transferring happens in both directions that too simultaneously.

Eg: Two lane road where traffic flows in both the directions, communication through telephone etc.

33) Name the different types of network topologies and brief its advantages?

Top 37 Networking Interview Questions Network Topology is nothing but the physical or logical way in which the devices (like nodes, links, and computers) of a network are arranged. Physical Topology means the actual place where the elements of a network are located.

Logical Topology deals with the flow of data over the networks. A Link is used to connect more than two devices of a network. And more than two links located nearby forms a topology.

The network topologies are classified as mentioned below

1) Bus Topology: In Bus Topology, all the devices of the network are connected to a common cable (also called as the backbone). As the devices are connected to a single cable, it is also termed as Linear Bus Topology.

The advantage of bus topology is that it can be installed easily. And the disadvantage is that if the backbone cable breaks then the whole network will be down.

2) Star Topology: In Star Topology, there is a central controller or hub to which every node or device is connected through a cable. In this topology, the devices are not linked to each other. If a device needs to communicate with the other, then it has to send the signal or data to the central hub. And then the hub sends the same data to the destination device.

The advantage of the star topology is that if a link breaks then only that particular link is affected. The whole network remains undisturbed. The main disadvantage of the star topology is that all the devices of the network are dependent on a single point (hub). If the central hub gets failed, then the whole network gets down.

3) Ring Topology: In Ring Topology, each device of the network is connected to two other devices on either side which in turn forms a loop. Data or Signal in ring topology flow only in a single direction from one device to another and reaches the destination node.

The advantage of ring topology is that it can be installed easily. Adding or deleting devices to the network is also easy. The main disadvantage of ring topology is the data flows only in one direction. And a break at a node in the network can affect the whole network.

4) Mesh Topology: In a Mesh Topology, each device of the network is connected to all other devices of the network. Mesh Topology uses Routing and Flooding techniques for data transmission.

The advantage of mesh topology is if one link breaks then it does not affect the whole network. And the disadvantage is, huge cabling is required and it is expensive.

34) What is the full form of IDEA?

IDEA stands for International Data Encryption Algorithm.

35) Define Piggybacking?

Top 37 Networking Interview Questions In data transmission if the sender sends any data frame to the receiver then the receiver should send the acknowledgment to the sender. The receiver will temporarily delay (waits for the network layer to send the next data packet) the acknowledgment and hooks it to the next outgoing data frame, this process is called as Piggybacking

36) What do you understand by TCP/IP?

TCP/IP is short for Transmission Control Protocol /Internet protocol. It is a set of protocol layers that is designed for exchanging data on different types of networks.


37) What is netstat?

The “netstat” is a command line utility program. It gives useful information about the current TCP/IP setting of a connection.