Hello, you basically want one router to prepend two ASNs for one hop, if I understand correctly. That's not an intuitive / default-worthy behavior.
On Thu, Oct 10, 2024 at 10:20:51AM +0000, Ochalski, Radoslaw via Bird-users wrote: > Here you have same route exported via Juniper border, local ASN 20940 is > prepended by default: > > inet.0: 955317 destinations, 2138917 routes (950415 active, 218793 holddown, > 14419 hidden) > Prefix Nexthop MED Lclpref AS path > * 20.135.0.0/16 Self 20940 8075 I > > vs bird: > > BGP.as_path: 8075 > > [truncated] BIRD shows the route after filters but _before_ BGP applies the export modifications, which includes prepending the local AS to the AS path iff the session is EBGP. I expect that Juniper is showing the route as-it-goes-to-the-wire. BIRD 2 doesn't allow showing routes that way; this is possible in BIRD 3 with `export table on` by showing routes from the export table. If you capture tcpdump from BIRD, you'll see the AS prepended. Maria -- Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o.
