Network Resilience by Design

The internet was designed to survive failures, and that resilience has been tested repeatedly. When undersea cables are severed by anchors or earthquakes, traffic can reroute through other paths, but the timing depends on the network layer and the failure.

BGP is the system that exchanges reachability between networks, acting less like instant GPS and more like a constantly updated set of road announcements. Some local failover mechanisms react very quickly, but global BGP convergence after route changes can take seconds or minutes, especially for withdrawals.

This resilience has limits. Centralization creates new vulnerabilities — when AWS experiences an outage, thousands of services go down because they depend on the same infrastructure. The internet's physical layer is decentralized, but its service layer has become dangerously concentrated in a handful of companies.