Top 30 Computer Networks Interview Questions and Answers
These computer networks interview questions are frequently asked in freshers, experienced, and technical round interviews. Each answer is written in simple language with real-world context, exactly how interviewers expect.
Basic Computer Networks Interview Questions
1. What is a computer network?
A computer network is a group of interconnected devices that share data, resources, and services using communication protocols like TCP/IP.
2. What are the types of computer networks?
LAN – Local Area Network
WAN – Wide Area Network
MAN – Metropolitan Area Network
PAN – Personal Area Network
3. What is LAN?
LAN connects devices within a small area such as an office, school, or home using Ethernet or Wi-Fi.
4. What is WAN?
WAN connects multiple LANs over large distances, such as the internet or corporate branch networks.
5. What is an IP address?
An IP address is a unique identifier assigned to a device on a network for communication.
6. Difference between IPv4 and IPv6?
IPv4 uses 32-bit addresses
IPv6 uses 128-bit addresses and solves IP exhaustion
7. What is a MAC address?
A MAC address is a unique hardware address assigned to a network interface card (NIC).
8. What is DNS?
DNS converts domain names (google.com) into IP addresses so computers can locate servers.
9. What is the OSI model?
The OSI model is a 7-layer framework that explains how data moves through a network.
10. Name the 7 OSI layers
Physical
Data Link
Network
Transport
Session
Presentation
Application
Intermediate Computer Networks Interview Questions
11. Difference between TCP and UDP?
TCP is reliable and connection-oriented, while UDP is faster and connectionless.
12. What is a router?
A router connects different networks and forwards data packets based on IP addresses.
13. What is a switch?
A switch connects devices within a LAN using MAC addresses.
14. What is subnetting?
Subnetting divides a network into smaller networks to improve performance and security.
15. What is NAT?
NAT allows multiple devices to share one public IP address.
16. What is a firewall?
A firewall filters incoming and outgoing network traffic based on security rules.
17. What is HTTP and HTTPS?
HTTPS is a secure version of HTTP that encrypts data using SSL/TLS.
18. What is bandwidth?
Bandwidth is the maximum data transfer capacity of a network.
19. What is latency?
Latency is the delay between sending and receiving data over a network.
20. What is packet loss?
Packet loss occurs when data packets fail to reach their destination.
Advanced Computer Networks Interview Questions
21. What happens when you type a URL in a browser?
DNS lookup → TCP connection → HTTPS encryption → server response → page rendering.
22. What is DHCP?
DHCP automatically assigns IP addresses to devices on a network.
23. What is ARP?
ARP maps an IP address to a MAC address within a local network.
24. What is a proxy server?
A proxy acts as an intermediary between users and the internet for security or caching.
25. What is load balancing?
Load balancing distributes traffic across multiple servers to improve availability.
26. What is VLAN?
VLAN logically separates networks within the same physical switch.
27. What is QoS?
Quality of Service prioritizes critical traffic like voice or video calls.
28. What is network topology?
Topology defines how devices are arranged in a network (star, mesh, bus, ring).
29. Difference between hub and switch?
A hub broadcasts data to all devices, while a switch sends data only to the target device.
30. How do you troubleshoot network issues?
Check physical connections → IP configuration → connectivity → DNS → firewall rules.
Final Note from ZProStudio
At ZProStudio, we believe technical knowledge should be clear, practical, and useful. These computer networks interview questions are curated to help you understand concepts deeply, not just memorize answers. For a deeper understanding of real-world networking fundamentals, you can also explore Cisco’s official Networking Basics guide.
👉 Next step:
Practice explaining these answers aloud and explore our tech interview & networking guides to stay interview-ready.