Computer Network Interview Questions

Today we will see a list of frequently asked computer network interview questions with answers. Let’s start!!!

Computer Network Interview Questions

Q1. What is a network?

Ans.

• A network is a collection of devices linked by a physical media link. A physical link connects two or more nodes in a network, or one or more nodes connect two or more networks.
• A network is a collection of devices that are linked together to allow data to be shared.
• The internet is an example of a network. Millions of people all over the world are connected by the internet.

Q2. What are the factors that affect the security of a network?

Ans. There are primarily two factors that influence security:

• Unauthorised access from an unauthenticated user
• Malicious code such as viruses

Q3. What are the factors that affect the reliability of a network?

Ans. A network’s reliability is influenced by the following factors:

• Failures are common.
• The time it takes for a network to recover after a failure.

Q4. What are the factors that affect the performance of a network?

Ans. A network’s performance is influenced by the following factors:

• Number of users
• Types of transmission medium available
• Hardware
• Software

Q5. What is meant by bandwidth?

Ans. The upper and lower range frequencies of every signal have a limit. The bandwidth of a network is the distance between its upper and lower frequency limits.

Q6. What is NOS in computer Networking?

Ans. Network Operating System (NOS) is an acronym for Network Operating System. It is specialised software that connects a computer to the internet and allows it to communicate with other computers and connected devices.

NOS is the software that allows the device to communicate with other devices and share files.

Novel NetWare was the first network operating system, released in 1983. Windows 2000, Windows XP, Linux, and other operating systems are examples of NOS.

Q7. What is POP3?

Ans. The Post Office Protocol version 3 is abbreviated as POP3. POP is responsible for connecting to a client machine’s mail service. POP3 has two modes of operation: delete mode and keep mode.

Q8. What are the main elements of a protocol?

Ans. The following are the main elements of a protocol:

a. Syntax:

It specifies the data’s structure or format. It also specifies the sequence in which they are displayed.

b. Semantics:

It defines the meaning of each bit section.

c. Timing:

Timing describes two aspects of data transmission: when it should be sent and how quickly it can be sent.

Q9. What is Routing Information Protocol (RIP)?

Ans.

• Routing Information Protocol (RIP) is an acronym for Routing Information Protocol. The routers use it to send data from one network to the next.
• RIP is a dynamic protocol that uses the hop count algorithm to find the best route from a source to a destination over a network.
• This protocol is used by routers to exchange network topology information.
• Small and medium-sized networks can use this protocol.

Q10. What are the advantages of address sharing?

Ans. Instead of routing, address sharing provides a security benefit. Because host PCs on the Internet can only see the public IP address of the external interface on the computer providing address translation, not the private IP addresses on the internal network, address sharing is beneficial.

Q11. What is multiplexing in computer networking?

Ans. Multiplexing is a set of techniques used in networking to allow the transmission of multiple signals over a single data link at the same time.

Q12. Explain LAN (Local Area Network)?

Ans. LANs are commonly used to connect computers, laptops, and consumer electronics, allowing them to share resources (such as printers and fax machines) and exchange data. Enterprise networks are LANs that are used by businesses or organisations. There are two types of LAN networks: wireless LAN (which uses Wi-Fi to eliminate the need for wires) and wired LAN (achieved using LAN cable). Wireless LANs are becoming increasingly popular in places where installing wire is difficult.

Q13. What is a VPN (Virtual Private Network)?

Ans. The Virtual Private Network (VPN) is a private internet-based WAN (Wide Area Network). It enables the creation of a secure tunnel (protected network) over the internet between different networks (public network). A client can connect to the organization’s network remotely by using the VPN.

Q14. What are the advantages of using a VPN?

Ans. Following are the advantages of using a VPN:

• When compared to WAN connections, VPN is used to connect offices in different geographical locations remotely.
• VPNs are used to secure transactions and transfer confidential data between offices in different parts of the world.
• By utilising virtualization, a VPN keeps an organization’s information safe from any potential threats or intrusions.
• VPN encrypts internet traffic and hides the user’s identity online.

Q15. What are the HTTP and HTTPS Protocols?

Ans. The HyperText Transfer Protocol (HTTP) is a set of rules and standards that govern how information can be transmitted over the Internet (WWW). It facilitates communication between web browsers and web servers. It’s a ‘stateless protocol’ meaning that each command is unrelated to the one before it. TCP is the foundation for HTTP, which is an application layer protocol. By default, it uses port 80.

The HyperText Transfer Protocol Secure, also known as Secure HTTP, is a secure version of the HyperText Transfer Protocol. It’s a more sophisticated and secure version of HTTP. The SSL/TLS protocol is used to provide security on top of HTTP. It enables secure transactions by encrypting communication and also assists in the secure identification of network servers. By default, port 443 is used.

Q16. What is the SMTP Protocol?

Ans. The Simple Mail Transfer Protocol (SMTP) stands for Simple Mail Transfer Protocol. SMTP establishes the rules for server communication. This set of guidelines assists the software in sending emails over the internet. End-to-end and Store-and-Forward methods are both supported. On port 25, it is in always-listening mode.

Q17. What is DNS?

Ans. The Domain Name System (DNS) is an acronym for Domain Name System. It is regarded as the Internet’s device/services directory. It’s a hierarchical and decentralised naming system for Internet-connected devices and services. It converts domain names to IP addresses and vice versa. By default, it uses port 53.

Q18. What is the use of a router and how is it different from a gateway?

Ans. A router is a networking device that joins two or more network segments together. It manages the network’s traffic. It sends packets of information and data from the source to the destination, such as web pages, emails, images, and videos. It’s a network layer application. In addition to routing and regulating network traffic, gateways can also send data between two dissimilar networks, whereas a router can only send data between similar networks.

Q19. What is the TCP Protocol?

Ans. The Transmission Control Protocol/Internet Protocol (TCP/IP) is the Transmission Control Protocol/Internet Protocol. It’s a set of guidelines that determine how a computer connects to the Internet and how data is transmitted across the network. When more than one computer is connected to the network, it creates a virtual network and establishes the connection using the three-way handshake model, which makes it more reliable.

Q20. What is the UDP Protocol?

Ans. The User Datagram Protocol (UDP) is a datagram-based protocol. It is primarily used for multicasting and broadcasting purposes. Except for the three ways of handshaking and error checking, its functionality is nearly identical to that of the TCP/IP Protocol. It uses a simple transmission method that does not involve hand shaking, making it less reliable.

Q21. What do you mean by DHCP Protocol?

Ans. The Dynamic Host Configuration Protocol (DHCP) stands for Dynamic Host Configuration Protocol.

It’s an application layer protocol that allows devices on IP networks to auto-configure themselves to use TCP and UDP-based protocols. DHCP servers assign IP addresses and other network configurations to devices on an individual basis, allowing them to communicate over an IP network. It assists in obtaining the subnet mask, IP address, and DNS resolution. By default, it uses port 67.

Q22. What is a MAC Address and how is it related to NIC?

Ans. The Media Access Control address is referred to as the MAC address. It is a 48-bit or 64-bit unique identifier for network devices. It’s also known as the physical address associated with the Data Link Layer’s Network Interface Card (NIC). A network interface card (NIC) is a hardware component in a networking device that allows a device to connect to a network.

Q23. What is a subnet?

Ans. A subnet is a network within a network created by the subnetting process, which divides a network into subnets. It is used to improve the network’s routing efficiency as well as its security. The time it takes to extract the host address from the routing table is cut in half.

Q24. What is a firewall?

Ans. The firewall is a network security system that monitors and blocks incoming and outgoing traffic according to firewall security policies. It serves as a barrier between the internet (public network) and networking equipment (a private network). This can be a hardware device, a software program, or a hybrid of the two. It gives the network an extra layer of protection.

Q25. What is the FTP Protocol?

Ans. The File Transfer Protocol (FTP) is a method of transferring files between computers. It’s an application layer protocol for reliably and efficiently transferring files and data between hosts. It can also be used to download files to your computer from remote servers. By default, it uses port 27.

Q26. What is the ARP Protocol?

Ans. The ARP protocol stands for Address Resolution Protocol. It’s a network-level protocol that converts a device’s logical address (IP address) to its physical address (MAC address). It can also be used to obtain a device’s MAC address when it is attempting to communicate over a local network.

Q27. Describe the OSI Reference Model?

Ans. The Open System Interconnections (OSI) model is an ISO-based network architecture model. The OSI model is named after the fact that it is concerned with connecting systems that are open to communication with other systems.

There are 7 layers in the OSI model. The principles that led to the creation of the seven layers can be summarised as follows:

• If a different abstraction is required, create a new layer.
• Each layer should have a distinct purpose.
• Each layer’s function is determined by internationally standardised protocols.

Q28. What are nodes and links?

Ans.

a. Nodes:

A node is a network device that communicates with other devices. In a network, a node is a point of intersection. Within a network, it can send and receive data and information. Computers, laptops, printers, servers, modems, and other nodes are examples of nodes.

b. Links:

The connectivity between two nodes in a network is referred to as a link or edge. It specifies the type of connectivity (wired or wireless) between the nodes as well as the protocols that allow one node to communicate with another.

Q29. What are the different types of networks?

Ans.

a. Personal Area Network:

Allow devices to connect and communicate over a person’s range. Connecting Bluetooth devices, for example.

b. Local Area Network:

It’s a privately owned network that serves a single building, such as a home, office, or factory, and the area around it.

c. Metropolitan Area Network:

It connects and encompasses the entirety of the city.

d. Wide Area Network:

It usually encompasses a large geographic area, such as a country or continent. The Internet is the world’s largest wide-area network.

e. Global Area Network:

It’s also known as the Internet, and it uses satellites to connect the world. The Internet is also known as the Network of Wide Area Networks (WAN).

Q30. What are Unicasting, Anycasting, Multicasting and Broadcasting?

Ans.

a. Unicasting:

Unicasting is when a message is sent from a single source to a single node. This is a common method for establishing a new connection in networks.

b. Anycasting:

Anycasting occurs when a message is sent from the source to any of the nodes. It is primarily used to obtain content from any of the Content Delivery System servers.

c. Multicasting:

Multicasting is when a message is sent to a subset of nodes from a single source. Used to send the same data to multiple recipients at the same time.

d. Broadcasting:

Broadcasting is when a message is sent to all nodes in a network from a single source. In a local network, broadcasting is used by DHCP and ARP.

Summary

This was all about Computer Network Interview Questions with answers. These are frequently asked to students in interviews.