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> wrote:

* 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.