On 2020-08-25, Remi Locherer <remi.loche...@relo.ch> wrote: > On Tue, Aug 25, 2020 at 07:11:12AM -0000, Stuart Henderson wrote: >> On 2020-08-24, Claudio Jeker <cje...@diehard.n-r-g.com> wrote: >> > On Mon, Aug 24, 2020 at 04:36:10PM +0000, Laura Smith wrote: >> >> *> N 2001:db8:aaaa::/29 2001:db8:aaaa::1111:1 100 100 >> >> 64512 65500 i >> >> * N 2001:db8:aaaa::/29 2001:db8:aaaa::2222:2 100 100 >> >> 65500 65500 i >> >> >> >> In this example, both 64512 and 65500 are peers (med=100) but obviously >> >> 65500 65500 should be the preferred route. >> >> That's not obvious to me. (The behaviour would be the same with the more >> common localpref setting too). > > AS path length is the same for both cases and med is also the same. The > selected path comes from the peer with the lowest IP address I guess.
Or weight, optionally route-age, BGP ID/ORIGINATOR_ID. >> > Now it is a bit strange that an AS is prepending on peering. I wonder why >> > they do that (is their connection to the IX undersized?). >> > > Maybe AS 65500 just aranged a new peering with AS 64512 and now needs to > impose more traffic to suffice some peering agreements? > > Dr. Peering might give some hints. ;-) > http://drpeering.net/tools/HTML_IPP/ipptoc.html Guesses can be made, but a quick email might get a more accurate answer :) "Hi, I see you are padding your announcements at $IX and we are seeing you from other peers with the same path length, would you prefer we send to you directly or via 64512?"
