On 10/6/21 3:33 PM, Jon Lewis wrote:
On Wed, 6 Oct 2021, Michael Thomas wrote:
People have been anycasting DNS server IPs for years (decades?).
So, no.
But it wasn't just their DNS subnets that were pulled, I thought. I'm
obviously really confused. Anycast to a DNS server makes sense that
they'd pull out if they couldn't contact the backend. But I thought
that almost all of their routes to the backend were pulled? That is,
the DFZ was emptied of FB routes.
Well, as someone else said, DNS wasn't the problem...it was just one
of the more noticeable casualties. Whatever they did broke the
network rather completely, and that took out all of their DNS, which
broke lots of other things that depend on DNS.
Maybe the problem here is that two things happened and the article
conflated the two: the DNS infrastructure pulled its routes from the
anycast address and something else pulled all of the other routes but
wasn't mentioned in the article.
Mike
