Not so much a DNS failure as an 
"oops, where did the routes to our auth servers go?"
moment.

or, in this case, several moments...  ^_^;;

Matt
 

On Mon, Oct 4, 2021 at 9:07 AM Eric Kuhnke <eric.kuhnke@gmail.com> wrote:
https://downdetector.com/status/facebook/

Normally not worth mentioning random $service having an outage here, but this will undoubtedly generate a large volume of customer service calls.

Appears to be failure in DNS resolution.