Page MenuHomeVyOS Platform

BGP route reflector configuration broken due to T7760
Closed, ResolvedPublicBUG

Description

This is caused by the changes in https://vyos.dev/T7760


Hi,
I know my network is configured somewhat esoterically but this has broken my route reflectors that are reflecting routes for a different network inside a VRF
system has AS 4200000001 globally - the VRF was configured with AS203528

set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 address-family ipv4-unicast addpath-tx-all
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 address-family ipv4-unicast route-reflector-client
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 address-family ipv6-unicast addpath-tx-all
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 address-family ipv6-unicast route-reflector-client
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 description 'PRG1BR1'
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 remote-as 'internal'
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 timers connect '1'
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 update-source 'dum1'
set vrf name PUBLIC_VRF protocols bgp parameters route-reflector-allow-outbound-policy
set vrf name PUBLIC_VRF protocols bgp system-as '203528'

how this looks configured on FRR on the 09/17 nightly, working properly

router bgp 203528 vrf PUBLIC_VRF
 no bgp ebgp-requires-policy
 no bgp default ipv4-unicast
 bgp route-reflector allow-outbound-policy
 no bgp network import-check
...
 neighbor 192.168.248.12 remote-as internal
 neighbor 192.168.248.12 description PRG1BR1
 no neighbor 192.168.248.12 enforce-first-as
 neighbor 192.168.248.12 update-source dum1
 neighbor 192.168.248.12 timers connect 1

after the upgrade - note that "internal" effectively means that the remote AS is the system AS which is now 4200000001 so this is not going to work

set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 address-family ipv4-unicast addpath-tx-all
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 address-family ipv4-unicast allowas-in number '1'
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 address-family ipv4-unicast route-reflector-client
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 address-family ipv6-unicast addpath-tx-all
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 address-family ipv6-unicast allowas-in number '1'
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 address-family ipv6-unicast route-reflector-client
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 description 'PRG1BR1'
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 local-as 203528 no-prepend replace-as
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 remote-as 'internal'
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 timers connect '1'
set vrf name PUBLIC_VRF protocols bgp neighbor 192.168.248.12 update-source 'dum1'

and FRR

router bgp 4200000001 vrf PUBLIC_VRF
 no bgp ebgp-requires-policy
 no bgp default ipv4-unicast
 bgp route-reflector allow-outbound-policy
 no bgp network import-check
...
 neighbor 192.168.248.12 remote-as internal
 neighbor 192.168.248.12 local-as 203528 no-prepend replace-as
 neighbor 192.168.248.12 description PRG1BR1
 no neighbor 192.168.248.12 enforce-first-as
 neighbor 192.168.248.12 update-source dum1
 neighbor 192.168.248.12 timers connect 1

the problem is that VyOS doesn't let me configure the same "remote-as" as "local-as"

fabrizzio@PRG1RR3# commit 
[ vrf name PUBLIC_VRF protocols bgp ]
Neighbor "192.168.248.14" has local-as specified which is the same as
remote-as, this is not allowed!

however FRR doesn't care about this, I can configure it manually on FRR and make it work.

neighbor 192.168.248.12 remote-as 203528
neighbor 192.168.248.12 local-as 203528 no-prepend replace-as
neighbor 192.168.248.12 description PRG1BR1
no neighbor 192.168.248.12 enforce-first-as
neighbor 192.168.248.12 update-source dum1
neighbor 192.168.248.12 timers connect 1

Again I know this is a bit far fetched configuration but I would rather inform that the change & associated migration will cause breakage.

Best Regards,
Fabrizzio.

Details

Version
2025.10.01-0021-rolling
Is it a breaking change?
Unspecified (possibly destroys the router)
Issue type
Bug (incorrect behavior)