Computer Networks MCQs

Question 1

What is the main difference between TCP and UDP?

Accepted Answer

TCP is connection-oriented and guarantees reliable delivery, while UDP is connectionless and does not guarantee delivery

Answer

UDP is connection-oriented, while TCP is connectionless

Answer

Both protocols guarantee reliable delivery in exactly the same way

Answer

TCP is used only for streaming video, while UDP is used only for web browsing

Question 2

What is the purpose of DNS in computer networking?

Accepted Answer

To translate human readable domain names into IP addresses

Answer

To encrypt data sent over the internet

Answer

To assign IP addresses to devices automatically

Answer

To route traffic between different subnets

Question 3

What is the primary function of a firewall?

Accepted Answer

To monitor and control incoming and outgoing network traffic based on predetermined security rules

Answer

To physically connect two different networks together

Answer

To speed up internet connection by caching web pages

Answer

To assign domain names to IP addresses

Question 4

What does DHCP stand for and what does it do?

Accepted Answer

Dynamic Host Configuration Protocol, which automatically assigns IP addresses to devices on a network

Answer

Direct Hardware Connection Protocol, which links devices physically

Answer

Domain Host Configuration Process, which registers domain names

Answer

Data Handling Communication Protocol, which encrypts network traffic

Question 5

What is the purpose of the three-way handshake in TCP?

Accepted Answer

To establish a reliable connection between a client and server before data transfer begins

Answer

To terminate a connection safely after data transfer

Answer

To encrypt data before it is sent over the network

Answer

To compress data packets for faster transmission

Question 6

What is the difference between a MAC address and an IP address?

Accepted Answer

A MAC address is a fixed hardware identifier for a network interface, while an IP address is a logical address that can change based on the network

Answer

An IP address is fixed to hardware, while a MAC address changes with the network

Answer

Both addresses refer to exactly the same thing

Answer

A MAC address is used only for wireless devices

Question 7

What is the main purpose of Network Address Translation (NAT)?

Accepted Answer

To allow multiple devices on a private network to share a single public IP address

Answer

To assign a unique domain name to every device on a network

Answer

To encrypt traffic between two networks

Answer

To physically extend the range of a wireless network

Question 8

What is the difference between HTTP and HTTPS?

Accepted Answer

HTTPS encrypts data in transit using SSL/TLS, while standard HTTP sends data without encryption

Answer

HTTP is only used for images, while HTTPS is only used for text

Answer

HTTPS is slower and less secure than HTTP

Answer

There is no meaningful difference between the two protocols

Question 9

What is the function of a router in a computer network?

Accepted Answer

To forward data packets between different networks based on their destination IP address

Answer

To physically connect two computers using a single cable

Answer

To assign domain names to websites

Answer

To store website content locally for faster access

Question 10

What is bandwidth in the context of computer networks?

Accepted Answer

The maximum rate at which data can be transferred over a network connection in a given amount of time

Answer

The physical distance data must travel between two devices

Answer

The total number of devices connected to a network

Answer

The time delay between sending and receiving a data packet

Question 11

What is the purpose of a subnet mask in IP networking?

Accepted Answer

To divide an IP address into a network portion and a host portion

Answer

To encrypt IP addresses for security

Answer

To assign a unique MAC address to a device

Answer

To convert a domain name into an IP address

Question 12

What is the purpose of ARP (Address Resolution Protocol)?

Accepted Answer

To map an IP address to its corresponding MAC address on a local network

Answer

To translate domain names into IP addresses

Answer

To assign IP addresses automatically to new devices

Answer

To encrypt traffic on a wireless network

Question 13

What is the primary difference between a hub and a switch?

Accepted Answer

A hub broadcasts incoming data to all connected devices, while a switch sends data only to the intended recipient device

Answer

A switch broadcasts data to all devices, while a hub is more selective

Answer

Both devices behave identically in modern networks

Answer

A hub can only connect wireless devices

Question 14

What is latency in networking terms?

Accepted Answer

The time delay between sending a data packet and it arriving at its destination

Answer

The total amount of data that can be sent over a connection

Answer

The number of devices connected to a single router

Answer

The physical length of a network cable

Question 15

What is the purpose of the Transport layer in the OSI model?

Accepted Answer

To manage end-to-end communication and ensure reliable data transfer between devices

Answer

To physically transmit raw bits over a communication medium

Answer

To translate domain names into IP addresses

Answer

To manage the physical routing of packets across networks

Question 16

What does the term 'packet switching' refer to in networking?

Accepted Answer

Breaking data into small packets that are transmitted independently and reassembled at the destination

Answer

Sending an entire file as a single continuous stream without breaking it up

Answer

Physically switching cables between two devices

Answer

Encrypting data before it leaves the source device

Question 17

What is the function of the Application layer in the OSI model?

Accepted Answer

It provides the interface through which end user applications interact with network services, such as web browsers using HTTP

Answer

It handles the physical transmission of electrical signals

Answer

It manages routing decisions between networks

Answer

It converts data into binary format

Question 18

What is a VPN primarily used for?

Accepted Answer

To create a secure, encrypted connection over a public network, often to protect privacy or access restricted resources

Answer

To permanently increase internet connection speed

Answer

To assign static IP addresses to all devices on a network

Answer

To physically extend a wired network using fiber cables

Question 19

What is the purpose of a checksum in network data transmission?

Accepted Answer

To detect errors that may have occurred during data transmission by comparing calculated values

Answer

To encrypt data before sending it over the network

Answer

To compress data to reduce transmission time

Answer

To assign a priority level to network packets

Question 20

How many layers does the OSI model have?

Accepted Answer

Seven

Answer

Five

Answer

Four

Answer

Six

Question 21

What is the purpose of the Domain Name System (DNS) cache?

Accepted Answer

It temporarily stores previously resolved domain name lookups to speed up future requests

Answer

It permanently blocks certain websites

Answer

It stores the actual content of web pages

Answer

It encrypts all outgoing network traffic

Question 22

What is the main difference between IPv4 and IPv6 addresses?

Accepted Answer

IPv4 uses 32-bit addresses while IPv6 uses 128-bit addresses, allowing for a vastly larger address space

Answer

IPv4 addresses are always longer than IPv6 addresses

Answer

IPv6 can only be used on private networks

Answer

There is no real difference between the two protocols

Question 23

What is the function of the Session layer in the OSI model?

Accepted Answer

It manages and controls the connections, or sessions, between two communicating devices

Answer

It handles the physical transmission of bits over a cable

Answer

It is responsible only for encrypting data

Answer

It converts data into human readable text

Question 24

What is a MAC flooding attack in networking?

Accepted Answer

An attack that overwhelms a switch's MAC address table, forcing it to broadcast traffic to all ports like a hub

Answer

An attack that floods a network with too many DNS queries

Answer

An attack that only targets wireless routers

Answer

An attack that changes a device's IP address repeatedly

Question 25

What is the purpose of the Transmission Control Protocol (TCP) sliding window?

Accepted Answer

It controls how much data can be sent before requiring an acknowledgment, helping manage flow control

Answer

It encrypts data before it is sent over the network

Answer

It permanently blocks a connection after a fixed time

Answer

It is used only for wireless connections

Question 26

What is the difference between a public IP address and a private IP address?

Accepted Answer

A public IP address is reachable directly from the internet, while a private IP address is only used within a local network

Answer

A public IP address changes every second, while a private one never changes

Answer

Private IP addresses are always faster than public ones

Answer

There is no functional difference between the two

Question 27

What is the purpose of the Simple Mail Transfer Protocol (SMTP)?

Accepted Answer

It is used for sending email messages from a client to a server or between mail servers

Answer

It is used for downloading email messages onto a device

Answer

It is used only for browsing websites

Answer

It manages domain name registrations

Question 28

What does the term 'jitter' mean in the context of network performance?

Accepted Answer

The variation in delay experienced by packets as they travel across a network

Answer

The total amount of data a network can carry

Answer

The physical distance between two networked devices

Answer

The number of devices connected to a single router

Question 29

What is the purpose of a proxy server?

Accepted Answer

It acts as an intermediary between a client and other servers, often for caching, filtering, or anonymity

Answer

It permanently stores a copy of every website ever visited

Answer

It replaces the need for a router entirely

Answer

It is used only to block viruses

Question 30

What is the purpose of the Address Resolution Protocol (ARP) cache?

Accepted Answer

It stores recently resolved mappings between IP addresses and MAC addresses to avoid repeating the resolution process

Answer

It stores passwords used to access network devices

Answer

It permanently blocks unknown devices from a network

Answer

It stores DNS records for websites

Question 31

What is the difference between unicast, multicast, and broadcast communication?

Accepted Answer

Unicast sends data to a single recipient, multicast sends to a specific group, and broadcast sends to every device on the network

Answer

All three terms describe exactly the same type of communication

Answer

Unicast sends data to every device, while broadcast sends to only one

Answer

Multicast can only be used for video streaming

Question 32

What is the purpose of the Network layer in the OSI model?

Accepted Answer

It handles logical addressing and routing of data packets between different networks

Answer

It is responsible only for converting data into electrical signals

Answer

It manages application specific data formats

Answer

It handles error correction at the bit level only

Question 33

What is the purpose of a Content Delivery Network (CDN)?

Accepted Answer

It distributes copies of content across multiple servers in different locations to reduce latency for users

Answer

It permanently deletes outdated website content

Answer

It is used only to manage email delivery

Answer

It replaces the need for a domain name entirely

Question 34

What is the purpose of port numbers in networking?

Accepted Answer

They identify specific applications or services running on a device so data can be delivered to the correct process

Answer

They identify the physical location of a device

Answer

They are used only for wireless connections

Answer

They replace the need for an IP address

Question 35

What is the purpose of the Simple Network Management Protocol (SNMP)?

Accepted Answer

It is used to monitor and manage network devices such as routers and switches

Answer

It is used to send and receive email messages

Answer

It is used only to assign IP addresses

Answer

It converts domain names into IP addresses

Question 36

What does the term 'full duplex' mean in the context of network communication?

Accepted Answer

Data can be transmitted and received at the same time in both directions

Answer

Data can only be transmitted in one direction at a time

Answer

Data can never be transmitted and received simultaneously

Answer

It refers only to wireless connections

Question 37

What is the purpose of a wildcard mask in networking configurations?

Accepted Answer

It specifies which bits of an IP address should be checked or ignored, often used in routing and access control

Answer

It permanently hides a device's IP address

Answer

It converts an IP address into a domain name

Answer

It is used exclusively for wireless encryption

Question 38

What is the function of the Data Link layer in the OSI model?

Accepted Answer

It handles the reliable transfer of data frames between two directly connected nodes, including error detection

Answer

It is responsible for routing packets across different networks

Answer

It only manages the physical cabling used in a network

Answer

It handles application level data formatting

Question 39

What is the main advantage of using fiber optic cables over traditional copper cables for networking?

Accepted Answer

Fiber optic cables generally support higher bandwidth and longer transmission distances with less signal loss

Answer

Fiber optic cables are always cheaper to install than copper cables

Answer

Fiber optic cables cannot be damaged in any way

Answer

Copper cables are always faster than fiber optic cables

Question 40

What is the purpose of Quality of Service (QoS) settings on a network?

Accepted Answer

They prioritize certain types of network traffic to ensure important data, such as video calls, gets better performance

Answer

They permanently block low priority traffic from ever reaching its destination

Answer

They only apply to wired networks, never wireless ones

Answer

They are used exclusively to assign IP addresses

Question 41

What is the purpose of the File Transfer Protocol (FTP)?

Accepted Answer

It is used to transfer files between a client and a server over a network

Answer

It is used to browse websites

Answer

It is used only to send email attachments

Answer

It converts files into a compressed format automatically

Question 42

What is meant by the term 'network topology'?

Accepted Answer

The physical or logical arrangement of devices and connections in a network

Answer

The total speed at which a network can transmit data

Answer

The list of software installed on network devices

Answer

The set of rules used to encrypt network traffic

Question 43

What is the purpose of the Internet Control Message Protocol (ICMP)?

Accepted Answer

It is used to send error messages and operational information, such as with the ping command

Answer

It is used to transfer large files between servers

Answer

It is used only to encrypt network traffic

Answer

It assigns domain names to IP addresses

Question 44

What is the difference between a static IP address and a dynamic IP address?

Accepted Answer

A static IP address stays the same over time, while a dynamic IP address can change and is often assigned automatically by DHCP

Answer

A static IP address changes every few seconds

Answer

A dynamic IP address can only be used on wireless networks

Answer

There is no meaningful difference between them

Question 45

What is the purpose of a Virtual Local Area Network (VLAN)?

Accepted Answer

It logically divides a single physical network into multiple separate broadcast domains

Answer

It physically separates network cables from each other

Answer

It is used only to increase internet speed

Answer

It replaces the need for switches entirely

Question 46

Which layer of the OSI 7-layer model is responsible for end-to-end reliable data delivery and flow control?

Accepted Answer

Transport Layer

Answer

Network Layer

Answer

Data Link Layer

Answer

Session Layer

Question 47

Which layer of the OSI 7-layer model is responsible for end-to-end reliable data delivery and flow control?

Accepted Answer

Transport Layer

Answer

Network Layer

Answer

Data Link Layer

Answer

Session Layer

Computer Networks MCQ Questions

What is the main difference between TCP and UDP?

What is the purpose of DNS in computer networking?

What is the primary function of a firewall?

What does DHCP stand for and what does it do?

What is the purpose of the three-way handshake in TCP?

What is the difference between a MAC address and an IP address?

What is the main purpose of Network Address Translation (NAT)?

What is the difference between HTTP and HTTPS?

What is the function of a router in a computer network?

What is bandwidth in the context of computer networks?

What is the purpose of a subnet mask in IP networking?

What is the purpose of ARP (Address Resolution Protocol)?

What is the primary difference between a hub and a switch?

What is latency in networking terms?

What is the purpose of the Transport layer in the OSI model?

What does the term 'packet switching' refer to in networking?

What is the function of the Application layer in the OSI model?

What is a VPN primarily used for?

What is the purpose of a checksum in network data transmission?

How many layers does the OSI model have?

What is the purpose of the Domain Name System (DNS) cache?

What is the main difference between IPv4 and IPv6 addresses?

What is the function of the Session layer in the OSI model?

What is a MAC flooding attack in networking?

What is the purpose of the Transmission Control Protocol (TCP) sliding window?

What is the difference between a public IP address and a private IP address?

What is the purpose of the Simple Mail Transfer Protocol (SMTP)?

What does the term 'jitter' mean in the context of network performance?

What is the purpose of a proxy server?

What is the purpose of the Address Resolution Protocol (ARP) cache?

What is the difference between unicast, multicast, and broadcast communication?

What is the purpose of the Network layer in the OSI model?

What is the purpose of a Content Delivery Network (CDN)?

What is the purpose of port numbers in networking?

What is the purpose of the Simple Network Management Protocol (SNMP)?

What does the term 'full duplex' mean in the context of network communication?

What is the purpose of a wildcard mask in networking configurations?

What is the function of the Data Link layer in the OSI model?

What is the main advantage of using fiber optic cables over traditional copper cables for networking?

What is the purpose of Quality of Service (QoS) settings on a network?

What is the purpose of the File Transfer Protocol (FTP)?

What is meant by the term 'network topology'?

What is the purpose of the Internet Control Message Protocol (ICMP)?

What is the difference between a static IP address and a dynamic IP address?

What is the purpose of a Virtual Local Area Network (VLAN)?

Which layer of the OSI 7-layer model is responsible for end-to-end reliable data delivery and flow control?

Which layer of the OSI 7-layer model is responsible for end-to-end reliable data delivery and flow control?