Computer Networks Overview

What is Computer Networks

Computer networks study how computers reliably exchange data with each other. From browsing webpages to messaging apps to distributed systems — all depend on computer networks.

Why Learn Computer Networks

Foundation of all distributed systems. Microservices, cloud computing, distributed databases — all built on networking.

Interview essential. "TCP three-way handshake," "HTTP vs. HTTPS," "DNS resolution" — these appear in virtually every technical interview.

Core subject in CS entrance exams. ~25 points.

Core Knowledge Modules

Network Architecture

• OSI 7-layer model vs. TCP/IP 4-layer model
• Encapsulation and decapsulation

Network Layer

• IP protocol: IPv4, subnetting, CIDR
• Routing algorithms: Distance Vector (RIP), Link State (OSPF), Path Vector (BGP)

Transport Layer

• TCP: Three-way handshake, four-way teardown, sliding window, congestion control
• UDP: Connectionless, unreliable but efficient

Application Layer

• HTTP/HTTPS: Request methods, status codes, headers
• DNS: Domain resolution process

How to Learn

Top-down, starting from what you know. Recommended: Computer Networking: A Top-Down Approach.

Get hands-on with experiments. Use Wireshark to capture packets and see real TCP handshakes and HTTP requests.

Do the Stanford CS144 labs. Implement a TCP/IP protocol stack.

Resources in This Module