The Restless Aliases: the CNAME Layer re-crawled after 32 Days — 92.5% Held Still, 12.6 Million Rewired or Vanished, and the Biggest Moves Were Made by Platforms, Not People
Two CNAME-typed crawls of 1.9 billion hostnames, 32 days apart: 169 million cross-domain aliases followed by name. 7.5% of the alias layer rewires or disappears in one month, parking lost 1.54M aliases, one Chinese registrar generated 13% of all new aliases — and the three biggest 'migrations' were platforms re-pointing their own chains, dragging half a million customer domains along. For DNS operators, measurement researchers, and anyone who builds on someone else's CNAME.