Hi, We have observed strange behavior where BIRD is not adding ASN on EBGP export. Route is received on IBGP session within AS20940: r04.border01.lon03.fab > bird show config template bgp 4INTERECOR_ROUTERS template bgp '4INTERECOR_ROUTERS' { local as 20940; neighbor as 20940; r04.border01.lon03.fab> show route protocol 23.210.49.60__r24.lon02.ien for 20.135.0.0/16 all Executing "/usr/sbin/birdc show route protocol '23.210.49.60__r24.lon02.ien' for 20.135.0.0/16 all" Table master4: 20.135.0.0/16 unicast [23.210.49.60__r24.lon02.ien 2024-10-07] (100) [AS8075i] via 23.210.49.60 on ae1 Type: BGP univ BGP.origin: IGP BGP.as_path: 8075 BGP.next_hop: 23.210.49.60 BGP.med: 4294967294 BGP.local_pref: 350 Route ASPATH: 8075 which is expected. We are exporting this route on EBGP session from private ASN 4290006033 <-> to private ASN: 4290006002: r04.border01.lon03.fab> show route export 2a02:26f0:1880:3702::1__r01.stem01 for 20.135.0.0/16 all Executing "/usr/sbin/birdc show route export '2a02:26f0:1880:3702::1__r01.stem01' for 20.135.0.0/16 all" Table master4: 20.135.0.0/16 unicast [2.22.144.250__r01.sdn 2024-10-07 from 2.22.144.250] * (100) [AS8075i] via 23.210.49.60 on ae1 Type: BGP univ BGP.origin: IGP BGP.as_path: 8075 BGP.next_hop: 23.210.49.60 BGP.med: 4294967294 BGP.local_pref: 777 Route is received on 4290006002: r01.stem01.lon03.fab> show route protocol 2a02:26f0:1880:3702::__r04.border01 for 20.135.0.0/16 all Executing "/usr/sbin/birdc show route protocol '2a02:26f0:1880:3702::__r04.border01' for 20.135.0.0/16 all" Table master4: 20.135.0.0/16 unicast [2a02:26f0:1880:3702::__r04.border01 2024-10-07] * (100) [AS8075i] via 2a02:26f0:1880:3702:: on ae4 Type: BGP univ BGP.origin: IGP BGP.as_path: 4290006033 8075 BGP.next_hop: 2a02:26f0:1880:3702:: fe80::b6db:91ff:fe8b:1eb4 BGP.local_pref: 100 ASPATH: 4290006033 8075 We are missing AS 20940 on which essentially this prefix is received in our network!? Is this behavior expected? Kind Regards, Radek Ochalski