Assumptions about network designs...

Tue Jul 12 13:10:33 UTC 2022

This is actually not the case. Cable service in some regional areas was 
restored as late as on Monday and even in the same geographical area 
there was a partial connectivity, so it looks less probable that network 
could be overloaded only in some isolated segments longer than the rest 
of the network and require manual intervention to fix it.
OTOH, overloading network core of such big network should be hardly 
possible. Possible route "poisoning" could be isolated, so that it 
doesn't affect the whole network cost to cost. It must be very unlucky 
coincidence of such event to happen on such big scale. Maybe caused by 
HW or SW bug.
I'm talking just about probabilities of different scenarios and trying 
to compare them. So far, IMO provided version doesn't look very 
convincing.

Kind regards,
Andrey Kostin

sronan at ronan-online.com писал(а) 2022-07-11 20:18:
> I’m “guessing” based on all the services that were impacted the
> outage was likely cause by a change that caused a routing change in
> their multi-service network which overloaded many network devices, and
> by isolating the source the routes or traffic the rest of the network
> was able to recover.
> 
> But just a guess.
> 
> Shane
> 