“At 15:58 UTC we noticed that Facebook had stopped announcing the routes to their DNS prefixes.”
Facebook withdrew its own BGP routes and the internet forgot where it lived. Its DNS servers vanished with them, so Facebook, Instagram and WhatsApp went dark at once. Apps kept retrying and resolvers worldwide took 30 times their normal load. One config change took down three of the world’s biggest messaging services, and everyone else’s DNS paid for it.