Why Far-Flung Parts of the Internet Broke Today
VolumeDrive is a Pennsylvania-based hosting company that uses Cogent and (since late May of this year) Atrato for Internet transit. A routing leak this morning by VolumeDrive was passed on to the global Internet by Atrato causing disruptions to traffic in places as far-flung from the USA as Pakistan and Bulgaria.
Background
The way Internet transit is supposed to work in BGP is that a provider announces the global routing table to its customers (i.e., a large number of routes). Then, in turn, the customers announce local routes to their respective providers (generally a small number of routes). Each customer selects the routes it prefers from the options it receives. When a transit customer accidentally announces the global routing table to back one of its providers, things get messy. This is what happened earlier today and it had far-reaching consequences.
At 06:49 UTC this morning (18-September), VolumeDrive (AS46664) began announcing to Atrato (AS5580) nearly all the BGP routes it learned from Cogent (AS174). The resulting AS paths were of the following format:
… 5580 46664 174 …
Normally, VolumeDrive announces 39 prefixes (networks) to Atrato: 27 it originates itself and 12 it transits for two of its downstream Continue reading