Shaw routing issue 12 Aug 2014

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1

Hi Nanog, anyone know what's up with a nationwide (Canadian) routing issue
on Shaw?

http://www.theregister.co.uk/2014/08/12/nationwide_outage_at_canadian_isp_shaw/
https://community.shaw.ca/docs/DOC-3455

thanks
Leah

2

Maybe related to the 512k route issue?
http://www.bgpmon.net/what-caused-todays-internet-hiccup/

I've seen people reboot to recover from TCAM exception without adjusting
TCAM size only to run into the issue all over again. It's a fun way to
watch the problems roll around the network.

3

Outside looking in, but we did get a maintenance notice from Shaw in June for "Core Router reboot to resolve fully utilized IPv4 table"; let's hope for their sake they recarved TCAM while they're at it and that they don't have too many of those hiding around the network.

4

Pete Lumbis <alumbis@gmail.com> writes:

Maybe related to the 512k route issue?
What caused today’s Internet hiccup | BGPmon

I've seen people reboot to recover from TCAM exception without adjusting
TCAM size only to run into the issue all over again. It's a fun way to
watch the problems roll around the network.

In this case, it would probably have "helped" in the same way as
rebooting or waving a rubber chicken or whatever sometimes "helps": the
route issue was caused initially by a problem at Verizon that
caused them to deaggregate, which they fixed, so by the time someone had
identified the problem, paged someone, gotten them to the data center,
had a teleconference, rebooted the device, waited for it to come back
up... Verizon would have fixed it, so when it came back up it'd be
back under 512k again.

5

Yep. Most of the time I've seen this it's two data centers, both go TCAM
exception. You reboot DC1, when it comes back up you reboot DC2. This means
no iBGP learned routes so DC1 is fine. DC 2 is fine, until the iBGP peer
comes back and then start all over again.

6

Thanks for the info Pete, Geoffrey & Hugo!

LU