Not saying this is anything, but maybe someone else on here will see this and have a lightbulb moment...
All 3 DNS records for Facebook, Whatsapp and Instagram were updated on Sep 22.
https://whois.domaintools.com/facebook.com
https://whois.domaintools.com/whatsapp.com
https://whois.domaintools.com/instagram.com
I also noticed the same date on the other domains:
https://whois.domaintools.com/whatsapp.net
https://whois.domaintools.com/facebook.net
I am sure there are others. This could be just a simple Zuckerberg and Co. had something they changed/updated on that date for the entire FB empire, but I find a massive outage a few days (12) later to be really strange.
I do not have a whois premium account so I am unable to dig much further than this. Anything interesting happen on Sep 22?
The problem is that their network sent automatic router configuration messages to their peers, disconnecting itself from the outer world. No IP inside their network is now reachable, even if you have the IP, since the peers do no longer know how to route to it.
https://twitter.com/matthew1471/status/1445074113681399811
Nothing in their network is reachable. Internal communication systems, keycard access, you name it. They literally have to drive to the datacenter and plug cables in the routers now.
Archive of that Tweet -
BGP tells routers how to route to addresses.. New routes get announced. Prior to the issues they saw a load of "withdraw" route messages. Now no Internet provider knows how to get there.
https://archive.is/dQTcO