Network Fundamentals and Application Layer

reading · we frame, you read MIT or the canonical taught · we author, no canonical fits ↺ spirals back to earlier lessons

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Prerequisites

Systems Programming (C and Zig) not yet

Processes and Concurrency not yet

Complete prerequisites first to enroll.

reading · 30 min + ~221 min canonical

The Layered Model and Why the Network Is Slow

You build things on top of the web, and you probably do not fully understand the web. That is the normal state of affairs, not an insult — most application engineers treat the net…

primary Computer Networking: A Top-Down Approach — Kurose & Ross lecture videos (YouTube)

preview →

reading · 30 min + ~221 min canonical L1

The Link and Physical Layers: Bits on a Wire, Frames on a Link

At the very bottom of the stack, all the elegant abstractions dissolve into a physical fact: some medium — a copper wire, a fiber strand, a patch of radio spectrum — has to carry …

primary Computer Networking: A Top-Down Approach — Kurose & Ross lecture videos (YouTube)

after L1 locked

reading · 30 min + ~221 min canonical L1

HTTP and the Application Layer: From Plain Text to HTTP/3

Here is a fact that will change how you see your entire job: HTTP/1.1 is just text. A request is a method and a path, then headers that are plain key-value pairs separated by colo…

primary Computer Networking: A Top-Down Approach — Kurose & Ross lecture videos (YouTube)

after L2 locked

reading · 30 min + ~221 min canonical L1

DNS: The Internet's Distributed Directory

Before any HTTP request can happen, a name has to become an address. You type example.com; the machine needs 93.184.216.34. The system that performs this translation — the Domain …

primary Computer Networking: A Top-Down Approach — Kurose & Ross lecture videos (YouTube)

after L3 locked

reading · 35 min + ~221 min canonical L1

TLS and the Ruby Networking Stack: Sockets, Rack, and Net::HTTP

Two ideas close this quarter. First, TLS — the S in HTTPS — the layer that turns the open, eavesdroppable internet into something you can send a password over. Every padlock in yo…

primary Computer Networking: A Top-Down Approach — Kurose & Ross lecture videos (YouTube)

after L4 locked

exercise reading · 15 min L1

Exercises: Easy (Warm-up)

- [ ] Use dig and nslookup to trace DNS resolution for 5 domains — Record types A, AAAA, MX, CNAME, NS - [ ] Capture HTTP traffic with Wireshark — Identify GET/POST, headers, cook…

after L5 locked

exercise reading · 30 min L1

Exercises: Medium (Core)

- [ ] Build an HTTP/1.1 server in C from scratch — Parse request line and headers, serve static files, handle 200/404/500 - [ ] Implement a DNS resolver in C — Send UDP query to r…

after L6 locked

exercise reading · 45 min L1

Exercises: Hard (Stretch)

- [ ] Build a WebSocket server in Ruby — Implement handshake upgrade, frame parsing, ping/pong - [ ] Implement TLS 1.3 handshake concepts — Diffie-Hellman key exchange demo in Rub…

after L7 locked

exercise reading · 60 min L1

Mini-Project

- [ ] Build a multi-threaded HTTP server in C — Support concurrent connections (thread per connection), static file serving, basic routing, access logging, graceful shutdown on SI…

after L8 locked

L10

project reading · 360 min L1

Project: HTTP Client from Scratch in C

Implement an HTTP/1.1 client using raw TCP sockets. Support GET and POST requests, parse response headers and body, handle chunked transfer encoding, follow redirects. No libcurl.…

after L9 locked

L11

project reading · 360 min L1

Project: DNS Resolver in Ruby

Build a DNS resolver that sends UDP queries to a root server, follows referrals through TLD and authoritative servers, and resolves a domain name to an IP address. Support A, AAAA…

after L10 locked

L12

project reading · 600 min L1

Capstone: HTTP/1.1 Web Server

- [ ] Milestone 1: TCP server accepting connections using std.net.StreamServer, reading raw bytes - [ ] Milestone 2: HTTP request parser — method, path, headers, body using Zig sl…

after L11 locked

L13

assessment reading · 63 min L1

Self-Assessment: Network Fundamentals and Application Layer

- [ ] Explain the TCP/IP model (4 layers). What happens at each layer? - [ ] How does DNS resolution work? Walk through what happens from typing a URL to getting an IP address. - …

after L12 locked

13 lessons. Read in order; spiral back when you need to. By the end you'll have used the core ideas twice — once on the abstract, once on something you'll meet at work next week.