by We have implemented back a few bgp communities on our backbone. Below a small guide about how to use it.
Bloc announcement to a specific upstream of 34872
Community: 34872, 21, <dst_asn>
This community tell to as34872 router to don’t announce the prefix to a specific upstream. It work with all transit and direct session we have over IXP.
This prefix can be also used to discard an IX whole route server, but it doesn’t impact specific ix member over a route server. You need to use the ixp community directly to filter out the required member over their route server.
Examples
Drop HE (as6939) : (34872, 21, 6939)
Drop DE-CIX MUN route server: (34872, 21, 47228)
How to have a list of our upstreams / peers
Everything is listed on our looking lass page here