[174812] in North American Network Operators' Group
cogent update suppression, and routing loops
daemon@ATHENA.MIT.EDU (ryanL)
Thu Oct 2 12:03:23 2014
X-Original-To: nanog@nanog.org
Date: Thu, 2 Oct 2014 09:03:15 -0700
From: ryanL <ryan.landry@gmail.com>
To: North American Network Operators Group <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
hi. relatively new cogent customer. is what i've stated in my subject line
kinda standard fare with them?
i've discovered that when i advertise a /24 from inside a larger /22 to XO,
(who peers with cogent), and then pull the /24 some time later, that cogent
holds onto the /24 and then bounces packets around in their network a bunch
of times for upwards of 8-10 minutes until they finally yank it. this
effectively blackholes traffic to my /24 for anyone that is using a path
thru cogent.
example: http://ryry.foursquare.com/image/0e0K1K0t0W2M
it's been a bit of a frustrating experience talking to their noc to
demonstrate it, but i'm able to duplicate it on demand. even pushing routes
using their communities to offload the circuit takes forever to propagate
even on their own looking-glasses.
thx
ryan
