nanog mailing list archives
Re: AS PATH limits
From: William Herrin <bill () herrin us>
Date: Sun, 1 Oct 2017 01:24:46 -0400
On Sun, Oct 1, 2017 at 1:05 AM, Ken Chase <math () sizone org> wrote:
I don't quite understand the exact situation that causes the issue - our cogent facing router (quagga .99.22 debian) was receiving the route but that session stayed up - it was it while sending or the other igp router (also quagga .99.22) receiving (I think the latter) that was crashing their session. Not quite sure why the cogent session didn't crash as well (or first, before propagating the bad route).
Hi Ken, Technically the route is not bad, just really inconsiderate. The bug happens when quagga sends the the long-AS path route to a peer. As I understand it, when the announcement is larger than one segment, Quagga double-counts the some of the bytes when computing the number of bytes in the AS path. It receives the announcement just fine, but then it corrupts what it sends to the neighbor who then chokes. Bug and patch here: https://lists.quagga.net/pipermail/quagga-dev/2017-September/033284.html Regards, Bill Herrin -- William Herrin ................ herrin () dirtside com bill () herrin us Dirtside Systems ......... Web: <http://www.dirtside.com/>
Current thread:
- Re: AS PATH limits, (continued)
- Re: AS PATH limits jim deleskie (Sep 20)
- Re: AS PATH limits Tom Beecher (Sep 20)
- Re: AS PATH limits craig washington (Sep 22)
- RE: AS PATH limits Jakob Heitz (jheitz) (Sep 21)
- Re: AS PATH limits Ken Chase (Sep 30)
- Re: AS PATH limits sthaug (Sep 30)
- Re: AS PATH limits jim deleskie (Sep 30)
- Message not available
- Re: AS PATH limits Ken Chase (Sep 30)
- Re: AS PATH limits Christopher Morrow (Sep 30)
- Re: AS PATH limits Ken Chase (Sep 30)
- Re: AS PATH limits William Herrin (Sep 30)
- Re: AS PATH limits Hank Nussbacher (Sep 30)
- Re: AS PATH limits Mikael Abrahamsson (Sep 30)
- Re: AS PATH limits sthaug (Sep 30)