Niels, you are correct about my initial tweet, which I updated in later tweets to clarify with a hat tip to Will Hargrave as thanks for seeking more detail. Cheers, Ryan On Tue, Oct 5, 2021 at 08:24 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.