(Googler, opinion is my own, I know nothing about this specific outage).
Google has LOTS of internal routing systems. BGP is about anouncing what IPs a given network can handle, which is not the case here.
Before hitting application level routing, I believe you hit the Maglev[0]. Seems unlikely this was the cause, as it would likely take down all services.
One of the first application layers balancers you hit that is well known is the GFE[1][2]. This is similar to an HTTP reverse proxy, but Google made. I could definitely see this as the cause.
Google has LOTS of internal routing systems. BGP is about anouncing what IPs a given network can handle, which is not the case here.
Before hitting application level routing, I believe you hit the Maglev[0]. Seems unlikely this was the cause, as it would likely take down all services.
One of the first application layers balancers you hit that is well known is the GFE[1][2]. This is similar to an HTTP reverse proxy, but Google made. I could definitely see this as the cause.
[0] https://static.googleusercontent.com/media/research.google.c...
[1] https://cloud.google.com/security/infrastructure/design#goog...
[2] https://landing.google.com/sre/workbook/chapters/managing-lo...