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/>