All lessons
routing
2 free lessons tagged routing across Computer Science, Programming. Each one is a short sequence of focused steps with narration and a five-question quiz at the end — take them in any order, no signup required.
Computer Science
intermediateIP Addressing and How Routing Decides
IP is the only layer the whole internet agrees on. Work through IPv4 and IPv6 addressing, CIDR subnet math by hand, what a routing table really holds, longest-prefix match, why NAT ended end-to-end addressing, and how one BGP announcement can pull a network off the internet.
12 steps·~18 min
Programming
intermediateNext.js App Router Fundamentals
Next.js 15 App Router: page/layout/loading/error files, nested layouts, dynamic and catch-all segments, route groups, parallel routes, and the Metadata API for SEO — with the file tree as a diagram.
10 steps·~15 min