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
