IPv6 and CDN's

Mon Nov 29 01:33:45 UTC 2021

Dave Bell wrote:

>> That facebook poorly managed their DNS to cause the recent disaster
>> is an important evidence to support my point that DNS, so often, may
>> not be helpful for network operations against disastrous failures,
>> including, but not limited to, DNS failures.

> I don't want to wade into the middle of this argument, but has there been
> more information about the recent facebook outage released that I missed?

You should have missed:

https://engineering.fb.com/2021/10/05/networking-traffic/outage-details/
The end result was that our DNS servers became unreachable even though 
they were still operational. This made it impossible for the rest of the 
internet to find our servers.

> All I've read seems to say that the loss of connectivity to their DNS
> servers was a symptom, rather than the cause of the outage.

See above.

Another part of the release should also be interesting:

    and second, the total loss of DNS broke many of the internal
    tools we'd normally use to investigate and resolve outages
    like this.

That is an evidence for my statement above "that DNS, so often,
may not be helpful for network operations against disastrous
failures".

You can't rely on automatic tools over DNS, when DNS is failing.

					Masataka Ohta