Does anyone have info whether this network 69.171.240.0/20 was reachable during the outage. Jean From: NANOG <nanog-bounces+jean=ddostest.me@nanog.org> On Behalf Of Tom Beecher Sent: October 5, 2021 10:30 AM To: NANOG <nanog@nanog.org> Subject: Re: Facebook post-mortems... People keep repeating this but I don't think it's true. My comment is solely sourced on my direct observations on my network, maybe 30-45 minutes in. Everything except a few /24s disappeared from DFZ providers, but I still heard those prefixes from direct peerings. There was no disaggregation that I saw, just the big stuff gone. This was consistent over 5 continents from my viewpoints. Others may have seen different things at different times. I do not run an eyeball so I had no need to continually monitor. On Tue, Oct 5, 2021 at 10:22 AM Niels Bakker <niels=nanog@bakker.net <mailto:nanog@bakker.net> > wrote: * telescope40@gmail.com <mailto:telescope40@gmail.com> (Lou D) [Tue 05 Oct 2021, 15:12 CEST]:
Facebook stopped announcing the vast majority of their IP space to the DFZ during this.
People keep repeating this but I don't think it's true. It's probably based on this tweet: https://twitter.com/ryan505/status/1445118376339140618 but that's an aggregate adding up prefix counts from many sessions. The total number of hosts covered by those announcements didn't vary by nearly as much, since to a significant extent it were more specifics (/24) of larger prefixes (e.g. /17) that disappeared, while those /17s stayed. (There were no covering prefixes for WhatsApp's NS addresses so those were completely unreachable from the DFZ.) -- Niels.