On Thu, 2 Oct 2014, ryanL wrote:
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.
Perhaps related, I made an as-path prepend change on a route advertised to Cogent yesterday and noticed it took about 10 minutes for that change to propagate throughout Cogent's network and be visible on route-views. A moment later, I did the same thing with another carrier, and got the expected nearly instant gratification. Perhaps they've got a bunch of routers configured with minimum-advertisement-interval to batch the BGP updates and if you're unlucky with the timing, it can take a while for routes/changes to percolate through their network? Imagine driving down a long road, where every traffic light turns red just before you get to the intersection. Wait a minute here, wait a minute there... ---------------------------------------------------------------------- Jon Lewis, MCP :) | I route | therefore you are _________ http://www.lewis.org/~jlewis/pgp for PGP public key_________