Randy Monroe via NANOG wrote:
Updated: https://engineering.fb.com/2021/10/05/networking-traffic/outage-details/
So, what was lost was internal connectivity between data centers.
That facebook use very short expiration period for zone
data is a separate issue.
As long as name servers with expired zone data won't serve
request from outside of facebook, whether BGP routes to the
name servers are announced or not is unimportant.
Masataka Ohta
