[169605] in North American Network Operators' Group
RE: valley free routing?
daemon@ATHENA.MIT.EDU (Siegel, David)
Wed Mar 5 16:48:51 2014
From: "Siegel, David" <David.Siegel@Level3.com>
To: William Herrin <bill@herrin.us>, Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Date: Wed, 5 Mar 2014 21:48:26 +0000
In-Reply-To: <CAP-guGUmmojs+2C9AN-7RFTfik=vu0WP5e=xA-5GYkwPSXKKRQ@mail.gmail.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
I can't think of any circumstances where the business "B" would be content =
transit traffic between A and C without some form of compensation. That co=
mpensation may not involve payment for bits, however. In theory, the compe=
nsation might be derived from something occurring at the application layer,=
but even in those cases that business relationship is probably not apparen=
t from looking at prefix advertisements. Business B is probably using b2b =
user agents, gre encap or some other method that makes both legs look like =
independent IP flows to network A and B.
Interesting question, though.
Dave
-----Original Message-----
From: William Herrin [mailto:bill@herrin.us]=20
Sent: Wednesday, March 05, 2014 2:08 PM
To: Valdis Kletnieks
Cc: nanog@nanog.org
Subject: Re: valley free routing?
On Wed, Mar 5, 2014 at 4:00 PM, <Valdis.Kletnieks@vt.edu> wrote:
> On Wed, 05 Mar 2014 15:23:55 -0500, William Herrin said:
>> Can anyone tell me about a situation in which a route which was not=20
>> valley free was not a result of a misconfiguration or a bad actor?=20
>> For those who don't recall the terminology, a network path is valley=20
>> free if it crosses exactly zero or one free peering links when=20
>> traveling between the two endpoints.
>
> Assume 3 providers A B and C, where you have a single-homed customer=20
> on A and a single-homed customer on C, and A and C don't peer. =20
> Traffic may end up going thorugh an A-B peering and a B-C peering. And=20
> whether A-B and B-C are a free peering or a paid transit is a business=20
> deal, outside the scope of BGP, unless you want to abuse communities...
>
> Are A and/or C "bad actors" for not peering? Jury is still out on that on=
e.
Hi Valdis,
It's that business deal I want to hear about. When A-B and B-C are free pee=
ring but the traffic goes A-B-C for some reason other than a misconfigurati=
on or deliberate abuse. On or off list, I'd like to know about real-life us=
e cases where folks do this on purpose.
Regards,
Bill Herrin
--
William D. Herrin ................ herrin@dirtside.com bill@herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls C=
hurch, VA 22042-3004
