Networking Interview Questions

Difference Between TCP and UDP

TCP is a connection-oriented transport protocol that guarantees reliable, ordered, error-checked delivery through a handshake and acknowledgements, while UDP i…

What is the OSI Model?

The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes network communication into seven layers — Physical, Data Link, Network…

How Does DNS Work?

DNS (Domain Name System) is the internet’s phonebook: it translates human-readable domain names like example.com into the IP addresses machines use to connect,…

Difference Between HTTP and HTTPS

HTTP (HyperText Transfer Protocol) transfers web data in plain text, while HTTPS is the same protocol running over a TLS-encrypted connection — so HTTPS adds e…

What is an IP Address?

An IP address is a numeric label assigned to every device on a network so it can be uniquely identified and reached — IPv4 uses a 32-bit address written as fou…

What is Subnetting?

Subnetting is the practice of dividing a larger IP network into smaller, logically separated sub-networks (subnets) by borrowing bits from the host portion of…

What is the TCP Three-Way Handshake?

The TCP three-way handshake is the process a client and server use to establish a reliable connection before exchanging data: the client sends a SYN, the serve…

What is a MAC Address?

A MAC (Media Access Control) address is a 48-bit hardware identifier burned into a network interface card by its manufacturer, used to identify a device unique…

What is ARP (Address Resolution Protocol)?

ARP (Address Resolution Protocol) maps a known IP address to its corresponding MAC address on a local network, allowing a device to discover the physical hardw…

What is a Firewall?

A firewall is a network security system that monitors and controls incoming and outgoing traffic based on a defined set of rules, sitting between a trusted int…

What is NAT (Network Address Translation)?

NAT (Network Address Translation) is a technique that maps multiple private IP addresses on an internal network to one or a few public IP addresses, allowing m…

What is DHCP (Dynamic Host Configuration Protocol)?

DHCP (Dynamic Host Configuration Protocol) is a network protocol that automatically assigns IP addresses and other configuration details — like subnet mask, de…

Router vs Switch: What is the Difference?

A switch connects devices within a single local network and forwards frames between them using MAC addresses, while a router connects separate networks togethe…

What is a Proxy Server?

A proxy server is an intermediary that sits between a client and the destination server, forwarding requests and responses on the client’s behalf while optiona…

What is Latency vs Bandwidth?

Latency is the time it takes a single piece of data to travel from sender to receiver, while bandwidth is the maximum volume of data that can move through a co…

What is a VPN?

A VPN (Virtual Private Network) creates an encrypted tunnel between a device and a remote server, so traffic looks like it originates from that server and cann…

TCP/IP Model vs OSI Model

The OSI model is a seven-layer conceptual reference used for teaching and troubleshooting, while the TCP/IP model is a four-layer practical model that actually…

What is a Socket?

A socket is an endpoint for network communication, uniquely identified by the combination of an IP address, a port number, and a transport protocol (TCP or UDP…

What is SSL/TLS?

SSL/TLS is a cryptographic protocol that encrypts data in transit between a client and server, verifies the server’s identity using certificates, and ensures t…

HTTP/2 vs HTTP/1.1: What Changed?

HTTP/2 replaces HTTP/1.1’s text-based, one-request-per-connection model with a binary framing layer that multiplexes many requests and responses over a single…

IPv4 vs IPv6: What Are the Differences?

IPv4 uses 32-bit addresses giving about 4.3 billion possible addresses, while IPv6 uses 128-bit addresses giving a practically unlimited pool, and IPv6 also si…

What is Packet Switching?

Packet switching is a data transmission method that breaks messages into small, independently addressed packets, routes each one across the network based on cu…

What is the HTTP Request Lifecycle?

The HTTP request lifecycle is the full sequence a browser follows to load a resource: DNS resolution, TCP (and TLS) connection setup, sending the HTTP request,…

What is a Port in Networking?

A port is a 16-bit number (0–65535) that identifies a specific process or service on a device, letting a single IP address handle many simultaneous network con…