Top 30 Computer Networks Interview Questions and Answers 2025
Preparing for computer networks interviews can feel overwhelming, especially with so many concepts, protocols, and troubleshooting scenarios to master. At SSB Academy, we have helped hundreds of students build networking skills and secure jobs in IT companies, telecom firms, and cloud service providers.
Here’s a comprehensive list of the top 30 computer networks interview questions and answers that combine real-world insights, industry relevance, and practical examples—so you can walk into your interview with confidence.
Basic Computer Networks Interview Questions
1. What is a Computer Network?
A computer network is a system where two or more devices are connected to share data, resources, and services. Example: A LAN in an office connects employee computers to shared printers and servers.
2. What is the OSI Model?
The OSI Model has seven layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application. Each layer performs specific functions for data transmission.
3. What is the Difference Between LAN, MAN, and WAN?
LAN: Local Area Network, small area like offices
MAN: Metropolitan Area Network, city-level
WAN: Wide Area Network, global level (e.g., the Internet)
4. Define IP Address and Its Types
An IP address uniquely identifies devices on a network.
IPv4: 32-bit addressing (e.g., 192.168.1.1)
IPv6: 128-bit addressing, supports more devices (e.g., 2001:0db8::1)
5. What is a MAC Address?
A MAC (Media Access Control) address is a unique identifier assigned to network interface cards (NICs). Example: 00:1A:2B:3C:4D:5E.
6. Explain TCP and UDP Differences
TCP: Reliable, connection-oriented (used in web browsing, emails)
UDP: Faster, connectionless (used in video streaming, gaming)
7. What is a Subnet?
Subnetting divides a large network into smaller sub-networks for better security and performance.-
8. What is DNS and How Does It Work?
Domain Name System (DNS) converts human-readable domain names (e.g., google.com) into IP addresses.
9. What is DHCP?
Dynamic Host Configuration Protocol (DHCP) automatically assigns IP addresses to devices in a network.
10. What is NAT?
Network Address Translation (NAT) allows multiple devices in a private network to share a single public IP for Internet access.
10. What is NAT?
Network Address Translation (NAT) allows multiple devices in a private network to share a single public IP for Internet access.
Intermediate Networking Questions
11. Explain Routing and Switching
Routing: Finds the best path for data packets between networks
Switching: Transfers data within a local network
12. What is ARP?
Address Resolution Protocol (ARP) maps IP addresses to MAC addresses.
13. Explain VPN
A Virtual Private Network (VPN) creates a secure, encrypted connection over the Internet for remote users.
14. What are Firewalls and Their Types?
Firewalls protect networks by filtering traffic. Types: Packet-filtering, Stateful, and Next-Generation Firewalls (NGFWs).
15. What is Bandwidth vs. Latency?
Bandwidth: Amount of data transferred per second
Latency: Time delay in data transmission
16. What are VLANs?
Virtual LANs logically segment networks within the same switch for security and performance.
17. Explain Load Balancing
Load balancing distributes traffic across multiple servers to prevent overload and improve performance.
18. What is a Proxy Server?
A proxy server acts as an intermediary between users and the Internet, improving security and performance.
19. Difference Between Hub, Switch, and Router
Hub: Broadcasts data to all ports
Switch: Sends data to specific ports
Router: Connects different networks
20. What is MPLS?
Multiprotocol Label Switching (MPLS) speeds up data transmission by directing data along predetermined paths.
Advanced and Scenario-Based Questions
21. What is SDN?
Software-Defined Networking (SDN) separates the control plane from the data plane, enabling centralized network management.
22. What is Network Virtualization?
It combines hardware and software network resources into a single, software-based network.
23. Explain QoS (Quality of Service)
QoS prioritizes critical network traffic to ensure stable performance for voice/video calls.
24. What is Network Redundancy?
Network redundancy ensures high availability by providing backup paths for data in case of failure.
25. How Do You Troubleshoot Network Latency?
Check cabling and hardware
Use ping and traceroute tools
Monitor bandwidth usage
Verify firewall and routing rules
26. Explain the Three-Way Handshake in TCP
SYN → Client sends request
SYN-ACK → Server acknowledges
ACK → Client confirms connection
27. What is Network Security?
It involves firewalls, encryption, and access control to protect data and systems from attacks.
28. Difference Between Public and Private IP Addresses
Public IP: Accessible over the Internet
Private IP: Used within internal networks
29. What are Network Protocols?
Rules for data communication. Examples: HTTP, FTP, SMTP, SNMP.
30. Future of Computer Networks – SD-WAN & 5G
The future focuses on software-defined networks, edge computing, and ultra-low latency 5G networks for real-time applications.
Why Choose SSB Academy for Networking Training?
At SSB Academy, we help you:
Master core networking concepts through practical labs
Practice real interview questions with expert trainers
Access career support with mock interviews and job referrals
Check out our Computer Networking Courses at SSB Academy and start your IT career today.
