Welcome to Networking Interview Prep

This course covers the networking concepts interviewers actually probe on: how the internet works, the OSI model, IP addressing, TCP vs UDP, DNS, HTTP/HTTPS, TLS, and the full lifecycle of a web request. Not for network engineers — for developers who need to understand the infrastructure their code runs on.

What You'll Learn

• Networking Fundamentals - Packets, client-server model, P2P, and why developers need this
• OSI Model - All 7 layers, data encapsulation, and the TCP/IP comparison
• IP Addressing - IPv4, IPv6, subnetting, CIDR, and cloud VPC implications
• TCP and UDP - 3-way handshake, reliability, ports, sockets, and when to use each
• Application Protocols - HTTP, HTTPS, TLS/SSL, FTP, SFTP, and email protocols
• DNS - Resolution flow, record types, propagation, and debugging
• Diagnostic Tools - ping, traceroute, nslookup, curl, netstat
• Networking for Web Developers - Full web request journey, REST, WebSockets, CORS, CDN, and load balancers

How to Use This Course

Work through the chapters in order. Each lesson starts with a developer-focused hook, explains the concept with code examples and diagrams, and ends with the interview questions you will actually be asked. Use the sidebar to jump to specific topics once you know the shape.

Prerequisites

• Basic programming in any language
• Familiarity with making HTTP requests (fetch, axios, curl)
• No networking background required

Let's start with what a network actually is.