DNS pulling BGP routes?

Thu Oct 7 20:30:14 UTC 2021

On Thu, Oct 7, 2021 at 10:23 AM Masataka Ohta
<mohta at necom830.hpcl.titech.ac.jp> wrote:
> William Herrin wrote:
> > Facebook's _internal_ DNS, while not anycasted, followed a similar
> > logic: if the data center is isolated and their data goes stale, they
> > stop serving potentially wrong answers.
>
> As I already wrote, that is a standard mechanism of DNS with SOA
> expiration period as is documented in rfc1034

Then we agree: The failure mode was that after the data centers
disconnected from each other, all their DNS expired, breaking the
tools they'd normally use to recover. Facebook withdrawing the BGP
routes to its anycasted public DNS servers as they expired made no
difference.

Regards,
Bill Herrin

-- 
William Herrin
bill at herrin.us
https://bill.herrin.us/