DNS pulling BGP routes?
William Herrin
bill at herrin.us
Thu Oct 7 17:01:51 UTC 2021
On Thu, Oct 7, 2021 at 9:52 AM Masataka Ohta
<mohta at necom830.hpcl.titech.ac.jp> wrote:
> But, this time, the reality strikes back.
Not really. Or at all. Facebook the external service was down hard as
soon as the cross-datacenter connections all failed. Whether or not
the BGP routes for the external DNS were withdrawn had no impact on
the outage.
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. Since the routing failure
isolated all of the data centers, this left no usable _INTERNAL_ DNS
on which more or less everything else depends.
I didn't work for the DNS team when I worked as a production engineer
for Facebook but I worked close enough to understand what happened
from the posted description.
Regards,
Bill Herrin
--
William Herrin
bill at herrin.us
https://bill.herrin.us/
More information about the NANOG
mailing list