On Wed, 5 Oct 2005, Matthew Crocker wrote:
I'm curious where in your contract you think Cogent guaranteed you connectivity to Level 3?
My original contract was with NTT/Verio which Cogent purchased last year when Verio nuked their Boston POP. I'm having the contract dug out of the archives to look at what it says. IMHO I pay Cogent for Transit to the whole Internet, If I wanted partial transit or local peering I would order/contract and pay for that. Cogent is not currently providing me full transit service. I really don't care who pulled the plug, it is Cogents job to fix it for me as I am their customer.
"Isn't BGP supposed to work around this sort of thing?" This comes down to a little more than just "depeering" -- at least in the BGP sense. There's active route filtering going on as well if connectivity is dead; after all, I can bet the house that at least one of Cogent's network edge peers has connectivity to Level3, and vice versa.
From where I sit, I can see a plethora of routes that transit more than one tier1. And a few that transit three before hitting the origin. From a couple locations I see 3356 and 174 visible in *all* paths to the prefixes containing Level3 and Cogent in the path, respectively.
So perhaps the question you should be asking is: Why didn't routes for these networks fall over to the other upstream peers which *are* capable of moving the packets? Surely MCI, AT&T, Sprint, and others would carry the packets to the right place. I can see the paths right here....
Most transit contracts only guarantee packet delivery to the edge of their own networks. I'm pretty sure Cogent is doing that. (Hell, they have lots of spare capacity now. :)
Most also have a clause to cover the inter-AS links, making sure that they are not overloaded.
What nature of clause? I consider deliberately filtering prefixes or origin ASs to be a violation of common backbone BGP use. Too bad there aren't Equal Access laws for tier1s. <slyly evil grin> -- -- Todd Vierling <tv@duh.org> <tv@pobox.com> <todd@vierling.name>