Best 50 Computer Networks Interview Question and Answers For Fresher

Computer Networks Interview Questions For Freshers

computer networks interview questions for freshers computer networks interview questions for freshers

Q1) What is a computer network?

A computer network is a concept when one or more than one device connected with each other through the media or by using physical transmission medium in order to communicate or share the resources like data, applications, software or hardware, etc.

Q2) Why it is important to understand the computer network concept in networking?

In Networking It is really important to understand that how computers or electronic devices interact with one another. In a Computer network group of two or more computers that uses some standard set of communication protocols in order to exchange information with each other over some digital interconnections.

Q3) What are the types of computer networks?

WAN– Wide area network.

LAN– Local area network.

PAN– Personal area network.

CAN– Campus area network.

MAN– Metropolitan area network

WLAN– Wireless Local area network.

SAN– Storage area network



Q4) What is WAN?

 WAN means Wide area network. This type of network is used to connect two geographically separated locations. WAN helps to connect remotely to the big network for communication which is physically apart from each other. Internet is the best example of a Wide area network.

Q5) What is LAN?

 LAN is a local area network this type of network only can apply within a limited area like within 1m or can apply within the organization. LAN Network can maintain and manage by a single entity. Example – school, collages, residence.

Q6) What is PAN?

PAN is a Personal area network. PAN supports one to one communication like one person can communicate with another one or another organization. PAN generally use in a small sector where only a Small sort of communication required.

Q7) What is CAN?

CAN stands for campus area network. CAN is used on campus like school, colleges, hospitals, or in a small organization wherein one campus may have one or more buildings. In that case, if users want to share the data or resources with each other then the CAN network is used.

Q8) What is MAN?

MAN is a metropolitan area network. MAN is a network that is bigger than the LAN network but not more than WAN. MAN is used in cities, town, or in campus or organization also. Similar to the WAN network man also provide shared communication between the users. The concept of MAN is like a service provider but not for one organization

Q9) What is WLAN?

WLAN means wireless local area network. WLAN is a network generally we can see in Mobile devices laptops or tablets. This type of network does not rely on the physical network.

Q10) What is Internet?

 Internet is a typical public network It is considered as WAN (wide area network). We can access the internet globally means everyone can access the internet. It is a type of wan network but vast than WAN.

Q11) What is Intranet?

 An intranet is a private network. An intranet is similar to a local area network like it can only exist within the organization but the existence of this intranet is worldwide.

Q12) What is topology?

Network topology is a concept of computer networks and their physical representation. It describes how two or more computers that are in the network are physically represented.

Q13) What are the types of network topology?

There are five types of Network topology given below-

  1. Point to point topology.
  2. Bus topology.
  3. Ring topology.
  4. Star topology.
  5. Mesh topology.

Q14) What is Point to point topology?

In a point-to-point topology, two computers are directly connected with each other with the communication medium. Point to point topology is applicable to up to two or more hosts and this host connected with one single link.

Q15) What is Bus topology?

Bus topology is having serial bus like arrangement means all the computers are connected with each other in a serial manner. Bus topology consists of a backbone cable. Bus topology uses a half-duplex method for communication purposes.

Q16) What is Ring topology?

 Ring topology is a type of network topology In a Ring topology, computers are connected in a ring-like structure, and device in a ring topology is connected with two adjacent devices and share the data between them. Ring topology does not consist of the terminator.

Q17) What is Star topology?

 Star topology consists of the centralized concentrating device through which the computers are connected. The physical representation will look like a star like structure that is connected with a center called ad CCD (centralized concentrating device).

Q18) What is Mesh topology?

Mesh topology is a mixture of two or more topologies where every node and the network device are connected with each other. Mesh topology is widely used in wireless networks. Mesh topology is the oldest topology which is generally used in emergency cases like military areas or in smart buildings etc.

Q19) What is Transmission mode?

Transmission mode will define the mode of communication between two devices. Transmission mode consists of three types

  • Simplex mode
  • Half-duplex mode
  • Full duplex mode

Q20) What is Simplex mode?

 Simplex is unidirectional or one-directional. If two devices are communicating while one device is sending the data at that time another device can only receive it. Data transmission in the simplex mode is slower than another transmission mode because it is unidirectional.

Q21) What is Half-duplex mode?

In half-duplex when two devices are connected both the devices can transmit the data but not at the same moment. If two devices are communicating then both can send and receive data but not simultaneously means when one device sending the data other needs to wait.

Q22) What is a Full-duplex mode?

 In the full-duplex method, both the sender and receiver side can send and receive data simultaneously so that the rate of communication in full-duplex is high. Full duplex transmission is very efficient than the other transmission mode.

Q23) What are IP addresses and their class?

IP is a unique identification number which is given to the local computer for communication purpose. There are two parts of IP address first is a network and the second one is the host.

There are 5 classes and the range are given below-

Class A : –

Class B : –

Class C : –

Class D :

Class E : to

In the above classes A, B, C are used for general-purpose communication at the same time D class is used for multicast or two side communication with the group. E class is use research and development.

Q24) What is an Active Directory?

Active directory is a concept that is invented by Microsoft which is used for windows in a domain network. An inactive directory consists of a server which is known as a domain controller. Active Directory provides Authentication for all the users who are in the windows domain network and also provide security to them. The active directory also supports creating the admin users and also use in external devices.

Q25) What is a Domain?

The domain is a group of computers that supports the server-client relationship with a centralized administrative structure. All the users which are working in the domain environment are known as network users. The domain is highly secured at the same time it supports an unlimited no of computers or resources in a network.

Q26) What is a Workgroup?

In the windows operating system, if two or more or a group of computers are connected with each other in a network for sharing the data, files, application then this is known as a workgroup. Computers that are connected in the workgroup are independent means having no dependency. All the users which are working in the workgroup environment are known as local users. The workgroup environment is less secured as well as we only can connect 25 computers in a workgroup.

Q27) What is Router?

The router is a concept of routing the data packets which may contain important data, files, or resources from source to destination. It is a network device only use for sending and receiving the data packets in the computer networks.

Q28) What is Hub?

Hub is a networking device that is considered as no intelligent device with the multiport repeater. Hub Works at the physical layer of the OSI reference model. Hub works in half-duplex mode. Hub accepts the signal from one port and transmits it to all other ports.

Q29) What is a Switch?

The switch is also a networking device which is considered an intelligent device that performs switching from one port to another. Switch Works at the data link layer of the OSI reference model. It works in Half duplex mode.

Q30) What is Ipconfig?

The ipconfig command is used for displaying IP information of a computer for example DNS IP address and Gateway IP address.

Q31) What is Ping?

Ping is a packet internet groper. Ping command is used for checking the connection or connectivity between two computers. Ping will provide positive and negative acknowledgment. Ping will use port no 7 with TCP subprotocol and ICMP protocol.

Q32) What is Group policy?

Group policy is a concept through which you can give control over a user such that you can give some restrictions to the user like not allowing the user to change the wallpaper, not allowing to use a command prompt or snipping tool, not allowing the user to access the certain application, etc. The main purpose of the group policy is to provide security to the users in the organization.

 Q33) what is OU?

OU stands for organizational unit. OU in the active directory acts like a container that consists of users, groups in it. In OU group policy can be assigned by the administrator.

Q34) What is Default Gateway?

The default gateway is works as a router it is the Ethernet interface of the router which is used for sending and receiving data packets in the network.

 Q35) What is Subnet Mask?

A value that is always associated with an IP address this value is known as the subnet mask. It tells that which part of the IP address will belong to the network portion in the IP address and which belongs to the host portion.

 Q36) What is NIC?

NIC is a network interface card this NIC card is installed in the local computer so that it will help the computer to connect with the network. The purpose of this NIC card is to connect your computer to the network. NIC card consists of a MAC address that is used for the identification of a computer in a network.

Q37) What is MAC address?

MAC is a media access controller that is also considered as the physical address of your computer. MAC address is a fixed address assigned to your local computer. MAC address is encoded on the LAN card. MAC address is having 48 bits which is represented in hexadecimal format.

Q38) What is ICMP?

ICMP is an internet control message protocol. ICMP protocol is used for sending and receiving the data. This ICMP protocol works on the network layer. ICMP protocol is used for checking the communication between two network devices like data is reaching the destination with time or not.

Q39) Difference between static IP address and Dynamic IP address


Static IP address

Dynamic IP address

A static IP address is a fixed IP address like after assigning the static IP address it cannot be changed.

A dynamic IP address is not a fixed IP address. It can change every time when the user is connected with the network or change the network.

The Internet service providers can provide Static IP addresses.

Dynamic Host configuration DHCP can provide a Dynamic IP address every time.

A static IP address is less Secured.

A dynamic IP address is more secured


Q40) What is VPN?

VPN stands for a virtual private network. VPN is a highly secured network that is generally used in many organizations to provide secure communication. VPN network can be considered as a private wide area network over the internet. VPN is also used for remote connectivity at the same time it keeps each and every piece of information very secured. VPN supports token base system so that it is not easy to hack VPN connection.

Q41) What is the OSI model?

OSI Stands for open system interconnection, The OSI model is created by the ISO International organization of standardization. OSI model is a standard protocol suite or a reference model that defines a standard communication process between two hosts. OSI model is a 7 layer of Architecture that includes certain standard protocols on each and every layer of the OSI Model.

Seven layers are the Physical layer, Data link layer, Network layer, Transport layer, Session layer, Presentation layer, and application layer.

Q42) Explain seven layers of the OSI model

Physical layer- Physical layer is the first and lower level of the OSI reference model. Physical layer Consist of raw data. This layer converts raw data bits into the radio signals and then transmits them to the data link layer in the form of data packets.


Datalink layer- In the data link layer, these data packets from the physical layer will be converted into frames. This layer consists of the MAC address of your computer. This layer also helps to identify the error which is delivered from the physical layer.


Network layer- Data link layer transfers the data packets to the network layer and converts the data packet into a data segment. The network layer consists of an IP address. The IP address will help to transfer the data from one host to the destination host within the same network. The network layer supports logical addressing, routing, path determination, etc.


Transport layer- The transport layer consists of TCP and UDP protocol. The transport layer transfers the data to the correct destination with positive and negative acknowledgment. If the transmission fails then the transport layer keeps continuously tracking the data. The transport layer supports the segmentation flow control and error control.


Session layer- The session layer helps in session management. It provides correct authentication and authorization over the data. The transmission of the data in the session layer is in half-duplex or in the full-duplex mode.

Presentation layer- The presentation layer generally known as the syntax layer. The presentation layer helps to transmit the data in a format in which the application layer accepts it. This layer supports translation compression, encryption-decryption, etc.

Application layer– The application layer is the last layer of the OSI model. The application layer consists of network applications. For running such applications some standard protocols used in the application layer.

Example- HTTP, FTP, SMTP.

Q43) What is the TCP/IP model?

TCP /IP stands for transaction control protocol and internet protocol. TCP/IP model will help to determine how the data will pack transmit and route to the destination through the standard set of rules. This TCP protocol consists of 4 layers.

  • Application layer
  • Transport layer
  • Internet layer
  • Network access layer

Q44) Difference between TCP and UDP Protocol

TCP protocol

UDP protocol

TCP is a transmission control protocol.

UDP is a user datagram protocol.

TCP is a Connection-oriented protocol means it follows the path at the time of data transmission.

UDP is a connectionless protocol.

TCP is slow.

UDP is fast.

It is a reliable protocol.

It is an unreliable protocol.

TCP gives positive as well as negative acknowledgment.

TCP does not give any acknowledgment.

Example- HTTP, SMTP, FTP, POP3.

Example- DHCP, DNS.

Q45) What is telnet?

Telnet is a concept that is used for enabling the user to connect with the remote devices using a telnet client. Telnet is having post no 23. Telnet allows the user to manage their device remotely. If the user is having telnet in the local computer the user can manage their files or important data remotely by using telnet.

Q46) Difference between Ipv4 and Ipv6?



Ipv4 is having 32 Bit size IP address.

Ipv6 is having 128 Bit size IP address

Ipv4 consists of 5 classes from A to E.

Ipv6 can have an unlimited no of Ip address

While writing IPv4 address IP address is separated by a dot (.)

While writing IPv6 address IP address is separated by colon (:)

Ipv4 supports Unicast, Broadcast, Multicast

Ipv6 supports Anycast, Unicast, Multicast


Example- abc1:0000:0000:000a:


Q47) What is SMTP?

SMTP is a simple mail transfer protocol. This protocol is used to send the e-mail. This protocol works on the application layer of the TCP/IP protocol suite. SMTP is having port number 25. SMTP uses the MTA means mail transfer agent to transfer the e-mail to the correct address or destination.

Q48) What is FTP?

FTP is a file transfer protocol that is used to transfer important files with a server and client in a network. FTP protocol supports FTP client and FTP server so that it is having two port numbers. Port no 20 is used for transferring the files from client to server and port no 21 is for establishing a secured connection.

Q49) What is NFS?

NFS is a network file system. NFS allows the user to store and upload their important files, folders, and important document over the remote desktop. NFS is having port number 2049. This client-server application provides a secured platform where user can create their directory over the remote.


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