[85161] in North American Network Operators' Group
Re: Cogent/Level 3 depeering
daemon@ATHENA.MIT.EDU (Pete Templin)
Wed Oct 5 17:23:51 2005
Date: Wed, 05 Oct 2005 15:57:54 -0500
From: Pete Templin <petelists@templin.org>
To: "Justin M. Streiner" <streiner@cluebyfour.org>
Cc: nanog@nanog.org
In-Reply-To: <Pine.LNX.4.63.0510051537430.6354@whammy.cluebyfour.org>
Errors-To: owner-nanog@merit.edu
Justin M. Streiner wrote:
> Remember that when backbones peer with each other, they typically (and
> as normally dictated by peering policies on both sides) only announce
> their own routes and the routes of their downstream customers and agree
> not to announce a default route to each other. They do not announce a
> full routing table to each other. Upshot: When provider X de-peers
> provider Y, single-homed customers of either provider will likely have
> problems reaching single-homed sites of the other.
That assumes that both are transit-free networks. We've already heard
that Cogent buys some form of fill-in transit from Verio, perhaps for a
subset of {AOL/ATDN, Sprint, others}. Assuming such, why aren't routes
appearing in L3's routers with paths matching _2914_174_? L3 might be
filtering them out (automatically or manually; perhaps filters haven't
auto-generated yet), or Cogent might be requesting that they be filtered
(Verio's community structure allows this quite easily). Conversely, why
aren't routes appearing in Cogent's routers with paths matching
_2914_3356_? If Cogent is buying transit from Verio, they should be
receiving a full table.
Anyone have any inside connections to expose the truth(s) here?
pt
