On 10/6/21 2:58 PM, Jon Lewis wrote:
On Wed, 6 Oct 2021, Michael Thomas wrote:
On 10/6/21 2:33 PM, William Herrin wrote:
On Wed, Oct 6, 2021 at 10:43 AM Michael Thomas <m...@mtcc.com> wrote:
So if I understand their post correctly, their DNS servers have the
ability to withdraw routes if they determine are sub-optimal (fsvo).
The servers' IP addresses are anycasted. When one data center
determines itself to be malfunctioning, it withdraws the routes so
that users will reach a different data center that is, in theory,
still functioning.
Ah, I was wondering if the anycast part was the relevant bit. But
doesn't it seem odd that it would be intertwined with the DNS
infrastructure?
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.
Mike
