Basic Networking Interview Questions for Cybersecurity Freshers (2025 Guide)

If you're starting your career in cybersecurity, having a strong understanding of computer networking is essential. Many cybersecurity attacks, defenses, and tools are built on top of network structures. This blog highlights the most common networking interview questions asked to cybersecurity freshers and provides clear, beginner-friendly answers to help you prepare effectively.

Why Networking Knowledge Matters in Cybersecurity

A solid understanding of networking helps cybersecurity professionals detect, prevent, and respond to cyber threats more efficiently. Most attacks occur over networks—whether through ports, IP addresses, or malicious packets. That's why employers assess your grasp of networking concepts during interviews, even for entry-level roles.

Common Networking Interview Questions and Answers for Cybersecurity Freshers

What is a Network?

A network is a group of connected computers, devices, or nodes that communicate and share resources using defined communication protocols.

What is the Difference Between IP Address and MAC Address?

An IP address identifies a device logically on a network, while a MAC address is a physical address assigned to the device’s network interface card.

What is the Difference Between TCP and UDP?

TCP is connection-oriented, ensuring reliable data delivery, while UDP is connectionless, faster, and does not guarantee data delivery.
Example: TCP is used in web browsing and email; UDP is used in video calls and online gaming.

What is the OSI Model?

The OSI (Open Systems Interconnection) Model is a seven-layer framework used to understand and standardize network communication. The layers are:
Application, Presentation, Session, Transport, Network, Data Link, and Physical.

What are Common Network Devices?

Common network devices include routers, switches, hubs, firewalls, and access points. Each plays a role in directing and managing network traffic.

What is DNS?

DNS (Domain Name System) translates domain names like google.com into their corresponding IP addresses so browsers can load internet resources.

What is DHCP?

DHCP (Dynamic Host Configuration Protocol) automatically assigns IP addresses to devices on a network, simplifying network configuration.

What is a Subnet?

A subnet is a smaller portion of a larger network, created to improve performance and security by isolating traffic.

What is a Firewall?

A firewall is a security system that monitors and controls incoming and outgoing network traffic based on predefined rules.

What is the Role of a Router?

A router connects multiple networks together and directs data packets between them, typically from a local network to the internet.

What is a Switch?

A switch connects devices within a local area network (LAN) and uses MAC addresses to forward data only to the intended device.

What is NAT?

NAT (Network Address Translation) allows multiple devices in a private network to access the internet using one public IP address.

What is a Port Number?

A port number identifies a specific process or service on a device.
Example:

• HTTP: Port 80

• HTTPS: Port 443

• FTP: Port 21

• SSH: Port 22

What is ARP?

ARP (Address Resolution Protocol) resolves IP addresses to MAC addresses within a local network.

What is a VLAN?

A VLAN (Virtual LAN) groups devices into separate broadcast domains within the same physical network, improving security and management.

What is a VPN?

A VPN (Virtual Private Network) creates a secure tunnel for data to travel across public networks, ensuring privacy and encryption.

What is a Proxy Server?

A proxy server acts as an intermediary between the user and the internet, providing anonymity, caching, and content filtering.

What is Network Latency?

Network latency refers to the delay in data transmission. Low latency means quicker communication; high latency indicates slower response times.

What is Packet Sniffing?

Packet sniffing involves monitoring and capturing network packets using tools like Wireshark to analyze network traffic for troubleshooting or threat detection.

What is a Man-in-the-Middle (MITM) Attack?

A MITM attack occurs when a third party intercepts and potentially alters communication between two devices without their knowledge.

What is Port Scanning?

Port scanning is the act of probing a system for open ports, which can reveal vulnerabilities or services running on that device.

What is an IDS and IPS?

• IDS (Intrusion Detection System) detects and alerts on suspicious activity.

• IPS (Intrusion Prevention System) actively blocks malicious traffic.

What is ICMP?

ICMP (Internet Control Message Protocol) is used by network devices to send error messages and operational updates, often used in the ping command.

What is the Use of the Ping Command?

The ping command tests connectivity between two devices on a network by sending ICMP Echo Request messages and measuring response times.

What is Traceroute?

Traceroute is a tool that tracks the path packets take from a source device to a destination, showing each hop in the route.

What is a MAC Address?

A MAC (Media Access Control) address is a unique identifier assigned to a device's network interface card for communication on the physical network.

What is Network Segmentation?

Network segmentation divides a network into smaller parts to control traffic, improve performance, and enhance security.

What is the Difference Between Public and Private IP?

Public IP addresses are accessible over the internet, while private IP addresses are used within internal networks and not routable online.

What is Zero Trust Architecture?

Zero Trust is a security model where no device, user, or system is trusted by default, even if inside the corporate network. Every access request is verified.

What is a Loop in Networking?

A network loop occurs when data packets continuously circulate in the network due to misconfigured switches, causing congestion and failures.

What is DNS Spoofing?

DNS spoofing is a type of attack where fake DNS responses are sent to redirect users to malicious websites.

Conclusion

Understanding networking is essential for cybersecurity aspirants. These fundamental questions reflect what employers commonly ask during interviews for cybersecurity support, analyst, or SOC roles. Build your confidence by mastering these questions, practicing hands-on with tools like Wireshark, and staying updated with real-world applications of networking in cyber defense.

FAQ:

What is the OSI model and why is it important in networking?

The OSI model is a 7-layer framework that standardizes how data moves across a network. It helps troubleshoot issues and ensures interoperability between different systems.

What is the difference between TCP and UDP?

TCP is reliable and connection-oriented, ensuring all data arrives in order. UDP is faster but does not guarantee delivery, used for streaming and gaming.

What is an IP address?

An IP address is a unique identifier for a device on a network, allowing it to send and receive data.

What is a MAC address?

A MAC address is a hardware identifier for a device's network interface, used within local networks for device identification.

What is subnetting?

Subnetting divides a network into smaller segments to improve performance and security.

What is the difference between IPv4 and IPv6?

IPv4 uses 32-bit addressing and supports fewer devices. IPv6 uses 128-bit addresses, allowing for a much larger number of devices and better security.

What is DHCP?

DHCP automatically assigns IP addresses to devices on a network, simplifying network management.

What is DNS and how does it work?

DNS translates domain names like google.com into IP addresses that computers use to communicate.

What is NAT?

NAT translates private IP addresses to a public IP address, allowing multiple devices to access the internet using one IP.

What is a firewall?

A firewall filters network traffic based on predefined rules, blocking unauthorized access.

What is a VPN?

A VPN creates an encrypted connection over the internet, protecting data and user privacy.

What is ARP?

ARP maps IP addresses to MAC addresses, allowing devices to communicate within a local network.

What is ARP poisoning?

ARP poisoning is a cyberattack where a malicious actor sends fake ARP messages to intercept network traffic.

What is a port number?

Port numbers identify specific services on a device. For example, HTTP uses port 80.

What are some common network ports?

Port 80 (HTTP), Port 443 (HTTPS), Port 22 (SSH), Port 21 (FTP), Port 53 (DNS)

What is the difference between IDS and IPS?

IDS monitors and alerts on suspicious activity, while IPS actively blocks threats in real-time.

What does a switch do in a network?

A switch connects devices and sends data only to the destination device, reducing collisions.

What does a router do?

A router connects multiple networks and directs traffic between them.

What is a DMZ in networking?

A DMZ is a network segment that isolates public-facing servers from internal systems for security.

What is traceroute?

Traceroute tracks the path data takes from source to destination, useful for diagnosing network issues.

What is ping used for?

Ping checks connectivity between two devices and measures response time.

What is ICMP?

ICMP is used for sending error messages and operational information, often used by tools like ping.

What is a proxy server?

A proxy server acts as a gateway between users and the internet, providing security and anonymity.

What is network sniffing?

Network sniffing involves capturing and analyzing network traffic, useful for monitoring or malicious attacks.

How can network sniffing be prevented?

Encrypt communications, use secure protocols like HTTPS, and implement strong authentication.

What are honeypots?

Honeypots are decoy systems set up to detect and analyze attackers' behaviors.

What is a VLAN?

A VLAN creates separate logical networks within the same physical network to improve security and efficiency.

What is port scanning?

Port scanning detects open ports and services on a network, used for reconnaissance or auditing.

What are common networking tools used in cybersecurity?

Popular tools include Nmap (scanning), Wireshark (packet analysis), Snort (intrusion detection), and Nessus (vulnerability scanning).

What is zero trust architecture?

Zero trust means no user or device is trusted by default; every access request is verified.

Why is patching important in network security?

Patching closes known vulnerabilities, preventing attackers from exploiting outdated systems.