Most people never think about network protocols, and that is exactly how it should be. Protocols are the invisible agreements that let billions of devices, built by competing companies and running incompatible software, cooperate well enough to load a web page. They only become visible when they fail and when they fail at scale, the failure is spectacular.
This article walks through the four protocols that carry almost everything you do online:
IP and TCP: which move and order the bytes;
BGP: which decides which path those bytes take across the planet;
DNS: which turns human-friendly names into machine addresses;
