Computer Networking MCQs with answers covering LAN, WAN, OSI model, TCP/IP, protocols, and network devices for exams, interviews, and IT students. Computer Networking is a fundamental subject in information technology that focuses on the communication and connection between computers and devices. A strong understanding of networking concepts such as LAN, WAN, OSI model, TCP/IP, protocols, topologies, and network devices is essential for students, IT professionals, and competitive exam candidates. These Computer Networking MCQs are designed to strengthen conceptual knowledge, improve exam preparation, and enhance problem-solving skills. By practicing these multiple-choice questions, learners can quickly revise key topics, identify weak areas, and gain confidence for academic exams, interviews, and certification tests. This collection of carefully structured MCQs follows standard networking syllabi and supports both beginners and advanced learners.
Below are 100 Computer Networking MCQs written clearly in proper sequence (1–100), in simple English, each with four options and the correct answer.
Computer Networking – 100 MCQs
1. What is a computer network?
A. A single computer
B. A collection of connected computers
C. A computer program
D. A storage device
✅ Answer: B
2. Which device connects multiple computers in a LAN?
A. Router
B. Switch
C. Modem
D. Firewall
✅ Answer: B
3. What does LAN stand for?
A. Large Area Network
B. Local Area Network
C. Logical Area Network
D. Limited Area Network
✅ Answer: B
4. Which network covers the largest area?
A. PAN
B. LAN
C. MAN
D. WAN
✅ Answer: D
5. Which topology uses a central hub or switch?
A. Bus
B. Ring
C. Star
D. Mesh
✅ Answer: C
6. Which device forwards data based on MAC address?
A. Router
B. Switch
C. Modem
D. Repeater
✅ Answer: B
7. What does IP stand for?
A. Internet Provider
B. Internal Protocol
C. Internet Protocol
D. Information Process
✅ Answer: C
8. How many layers are there in the OSI model?
A. 5
B. 6
C. 7
D. 8
✅ Answer: C
9. Which OSI layer is responsible for routing?
A. Physical
B. Data Link
C. Network
D. Transport
✅ Answer: C
10. Which OSI layer handles encryption?
A. Session
B. Transport
C. Presentation
D. Network
✅ Answer: C
11. What does TCP stand for?
A. Transfer Control Protocol
B. Transmission Control Protocol
C. Technical Communication Protocol
D. Transport Core Protocol
✅ Answer: B
12. Which protocol is connectionless?
A. TCP
B. FTP
C. HTTP
D. UDP
✅ Answer: D
13. What is the default port number of HTTP?
A. 20
B. 21
C. 80
D. 443
✅ Answer: C
14. Which protocol is used to send emails?
A. POP3
B. SMTP
C. IMAP
D. FTP
✅ Answer: B
15. Which protocol is used to receive emails?
A. SMTP
B. FTP
C. POP3
D. SNMP
✅ Answer: C
16. What device regenerates signals?
A. Router
B. Switch
C. Repeater
D. Bridge
✅ Answer: C
17. Which topology uses a single backbone cable?
A. Star
B. Ring
C. Bus
D. Mesh
✅ Answer: C
18. What does DNS do?
A. Assigns IP addresses
B. Transfers files
C. Resolves domain names
D. Encrypts data
✅ Answer: C
19. Which protocol assigns IP addresses automatically?
A. ARP
B. DNS
C. DHCP
D. ICMP
✅ Answer: C
20. What does MAC stand for?
A. Machine Access Code
B. Media Access Control
C. Main Address Control
D. Multiple Access Channel
✅ Answer: B
21. Which address is permanent?
A. IP address
B. Port address
C. MAC address
D. Logical address
✅ Answer: C
22. Which OSI layer uses MAC addresses?
A. Network
B. Transport
C. Data Link
D. Physical
✅ Answer: C
23. Which topology is most reliable?
A. Bus
B. Ring
C. Star
D. Mesh
✅ Answer: D
24. What is a firewall used for?
A. Data storage
B. Network security
C. Signal transmission
D. Speed control
✅ Answer: B
25. Which cable uses light for data transmission?
A. Coaxial
B. Twisted pair
C. Ethernet
D. Fiber optic
✅ Answer: D
26. What command is used to test network connectivity?
A. FTP
B. Ping
C. Trace
D. Netstat
✅ Answer: B
27. What does FTP stand for?
A. Fast Transfer Protocol
B. File Transfer Protocol
C. File Transport Program
D. Fixed Transfer Process
✅ Answer: B
28. Which protocol is used for secure web browsing?
A. HTTP
B. FTP
C. HTTPS
D. SMTP
✅ Answer: C
29. What is bandwidth?
A. Data delay
B. Data loss
C. Data transfer rate
D. Signal error
✅ Answer: C
30. What is latency?
A. Network speed
B. Transmission delay
C. Data size
D. Cable length
✅ Answer: B
31. What does MAN stand for?
A. Main Area Network
B. Metropolitan Area Network
C. Medium Area Network
D. Multiple Area Network
✅ Answer: B
32. Which network is used for personal devices?
A. LAN
B. MAN
C. PAN
D. WAN
✅ Answer: C
33. Which protocol translates IP to MAC address?
A. DNS
B. DHCP
C. ARP
D. ICMP
✅ Answer: C
34. What is packet switching?
A. Dedicated connection
B. Data sent in packets
C. Signal boosting
D. Error checking
✅ Answer: B
35. Which topology is cheapest to implement?
A. Mesh
B. Ring
C. Star
D. Bus
✅ Answer: D
36. Which OSI layer ensures reliable data delivery?
A. Network
B. Transport
C. Session
D. Presentation
✅ Answer: B
37. What does VPN stand for?
A. Virtual Private Network
B. Verified Public Network
C. Visual Packet Network
D. Virtual Protocol Node
✅ Answer: A
38. Which address is logical?
A. MAC
B. IP
C. Hardware
D. Physical
✅ Answer: B
39. What is a node in networking?
A. Cable
B. Connection
C. Network device
D. Protocol
✅ Answer: C
40. Which device works at the Network layer?
A. Hub
B. Switch
C. Router
D. Repeater
✅ Answer: C
Computer Networking – MCQs (41–100)
41. What is the default port number of HTTPS?
A. 21
B. 80
C. 110
D. 443
✅ Answer: D
42. Which device works at the Physical layer of OSI model?
A. Router
B. Switch
C. Hub
D. Bridge
✅ Answer: C
43. What does ISP stand for?
A. Internet System Provider
B. Internal Service Provider
C. Internet Service Provider
D. Information Service Protocol
✅ Answer: C
44. What is the size of an IPv4 address?
A. 16 bits
B. 32 bits
C. 64 bits
D. 128 bits
✅ Answer: B
45. What is the size of an IPv6 address?
A. 32 bits
B. 64 bits
C. 96 bits
D. 128 bits
✅ Answer: D
46. Which switching technique is used by the Internet?
A. Circuit switching
B. Packet switching
C. Message switching
D. Time switching
✅ Answer: B
47. Which device converts digital signals to analog signals?
A. Router
B. Switch
C. Modem
D. Repeater
✅ Answer: C
48. Which OSI layer is responsible for session management?
A. Transport
B. Session
C. Network
D. Data Link
✅ Answer: B
49. Ethernet technology is based on which protocol?
A. CSMA/CA
B. Token Passing
C. CSMA/CD
D. TDMA
✅ Answer: C
50. Which IEEE standard is used for Wi-Fi?
A. 802.3
B. 802.5
C. 802.11
D. 802.15
✅ Answer: C
51. Which type of network has no central server?
A. Client-Server
B. Peer-to-Peer
C. Centralized
D. Distributed
✅ Answer: B
52. Which type of network uses a dedicated server?
A. Peer-to-Peer
B. PAN
C. Client-Server
D. MAN
✅ Answer: C
53. What is the data unit of the Network layer?
A. Bit
B. Frame
C. Segment
D. Packet
✅ Answer: D
54. What is the data unit of the Transport layer?
A. Packet
B. Frame
C. Segment
D. Bit
✅ Answer: C
55. What is the data unit of the Data Link layer?
A. Bit
B. Frame
C. Packet
D. Segment
✅ Answer: B
56. Which protocol is used for email retrieval while keeping emails on the server?
A. SMTP
B. FTP
C. POP3
D. IMAP
✅ Answer: D
57. What is phishing?
A. Network testing
B. Data encryption
C. Cyber attack
D. File transfer
✅ Answer: C
58. What is the main disadvantage of star topology?
A. High cost
B. Difficult installation
C. Central point failure
D. Low speed
✅ Answer: C
59. In ring topology, data flows in which direction?
A. Random
B. Star-shaped
C. Circular
D. Linear
✅ Answer: C
60. Which transmission media provides the highest speed?
A. Twisted pair
B. Coaxial cable
C. Fiber optic cable
D. Wireless
✅ Answer: C
61. What is the default port number of FTP?
A. 20
B. 21
C. 23
D. 25
✅ Answer: B
62. What does NAT stand for?
A. Network Access Technology
B. Network Address Translation
C. Network Allocation Table
D. Node Access Technique
✅ Answer: B
63. Which technology is used in Wireless PAN?
A. Wi-Fi
B. Bluetooth
C. Ethernet
D. Fiber
✅ Answer: B
64. Which device connects two LAN segments?
A. Router
B. Gateway
C. Bridge
D. Modem
✅ Answer: C
65. What is a hybrid topology?
A. Single topology
B. Wireless topology
C. Combination of topologies
D. Circular topology
✅ Answer: C
66. Which technique is used for error detection?
A. ARQ
B. CRC
C. FEC
D. Parity
✅ Answer: B
67. Network ID in an IP address identifies the:
A. Host
B. Router
C. Network
D. Protocol
✅ Answer: C
68. Host ID in an IP address identifies the:
A. Network
B. Host
C. Gateway
D. Port
✅ Answer: B
69. What is the broadcast address?
A. All bits 0
B. All bits 1
C. First address
D. Last usable address
✅ Answer: B
70. What is the loopback IP address?
A. 192.168.1.1
B. 10.0.0.1
C. 127.0.0.1
D. 255.255.255.0
✅ Answer: C
71. Which is a private IP address range?
A. 8.8.8.8
B. 172.16.0.0 – 172.31.255.255
C. 1.1.1.1
D. 224.0.0.0
✅ Answer: B
72. Which organization developed the OSI model?
A. IEEE
B. ISO
C. IETF
D. ITU
✅ Answer: B
73. Network congestion occurs when:
A. Network speed increases
B. Traffic exceeds capacity
C. Devices are idle
D. Signals are strong
✅ Answer: B
74. What is a Trojan?
A. Antivirus
B. Hardware device
C. Malware
D. Protocol
✅ Answer: C
75. Data confidentiality is ensured by:
A. Compression
B. Encryption
C. Routing
D. Switching
✅ Answer: B
76. Which OSI layer deals with bit transmission?
A. Physical
B. Data Link
C. Network
D. Transport
✅ Answer: A
77. Which topology offers maximum redundancy?
A. Bus
B. Ring
C. Star
D. Mesh
✅ Answer: D
78. Which protocol is used by the ping command?
A. TCP
B. UDP
C. ICMP
D. ARP
✅ Answer: C
79. Which protocol is used for network management?
A. SMTP
B. SNMP
C. FTP
D. HTTP
✅ Answer: B
80. Data transmission speed is measured in:
A. Hertz
B. Bytes
C. bps
D. Seconds
✅ Answer: C
81. DNS uses which structure?
A. Linear
B. Ring
C. Tree
D. Mesh
✅ Answer: C
82. Which protocol is used for secure remote login?
A. Telnet
B. FTP
C. SSH
D. SMTP
✅ Answer: C
83. Which cable has the least signal interference?
A. Twisted pair
B. Coaxial
C. Fiber optic
D. Ethernet
✅ Answer: C
84. Full duplex communication means:
A. One-way communication
B. Two-way communication at a time
C. Two-way communication simultaneously
D. No communication
✅ Answer: C
85. Half duplex communication example is:
A. Telephone
B. Television
C. Walkie-talkie
D. Radio
✅ Answer: C
86. What does NIC stand for?
A. Network Interface Card
B. Network Internet Controller
C. Node Interface Connection
D. Network Internal Card
✅ Answer: A
87. Collision mainly occurs in which device?
A. Switch
B. Router
C. Hub
D. Bridge
✅ Answer: C
88. Which device reduces network collisions?
A. Hub
B. Switch
C. Repeater
D. Modem
✅ Answer: B
89. Which IP version is most widely used today?
A. IPv1
B. IPv4
C. IPv5
D. IPv6
✅ Answer: B
90. The Internet is an example of:
A. LAN
B. MAN
C. PAN
D. WAN
✅ Answer: D
91. Network topology refers to the:
A. Network speed
B. Network layout
C. Network protocol
D. Network security
✅ Answer: B
92. A gateway connects networks with:
A. Same protocols
B. Same topology
C. Different protocols
D. Same speed
✅ Answer: C
93. A server provides:
A. Requests
B. Services
C. Errors
D. Signals
✅ Answer: B
94. A client sends:
A. Services
B. Errors
C. Requests
D. Signals
✅ Answer: C
95. DNS mainly uses which protocol?
A. TCP
B. UDP
C. FTP
D. ICMP
✅ Answer: B
96. Email attachment size depends on:
A. Client system
B. Network topology
C. Email server
D. Router
✅ Answer: C
97. Network reliability can be improved by:
A. Redundancy
B. Compression
C. Switching
D. Encryption
✅ Answer: A
98. What does QoS stand for?
A. Quality of System
B. Quantity of Service
C. Quality of Service
D. Quick Output System
✅ Answer: C
99. Which technique protects data from unauthorized access?
A. Routing
B. Encryption
C. Switching
D. Broadcasting
✅ Answer: B
100. A global network connecting millions of computers is called:
A. LAN
B. MAN
C. Intranet
D. Internet
✅ Answer: D
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