Page MenuHomeVyOS Platform

BFD was not enabled in BGP configuration
Open, NormalPublicBUG

Description

I setup a lab to connect VyOS rolling release 2025.04.04-0018-rolling with PVE EVPN feature.

PVE FRR configuation is below
If and only if, it will connect and work, when VyOS configure top level BFD with PVE IPs (even without BGP-BFD config in peer-group), even I used the same configuration with PVE FRR did, but VyOS will not send out any BFD packet to others.
PVE configuration works properly and I can capture BFD packet from VyOS.

with 1.4.1, I only need to enable VTEP peer-group bfd, I don't need protocol bfd peer XXXX

I also tested several rolling version and the behavior of VyOS is the same.

This might relate to FRR PR #17410 , and this is only in master and stable/10.3 branch (not 10.2 branch)
https://github.com/FRRouting/frr/pull/17410

VyOS Config (IP: 10.0.0.254)

protocols {
    bfd {
        peer 10.0.0.1 {
        }
        peer 10.0.0.2 {
        }
        peer 10.0.0.3 {
        }
    }
    bgp {
        address-family {
            l2vpn-evpn {
                advertise-all-vni
            }
        }
        neighbor 10.0.0.1 {
            peer-group VTEP
        }
        neighbor 10.0.0.2 {
            peer-group VTEP
        }
        neighbor 10.0.0.3 {
            peer-group VTEP
        }
        peer-group VTEP {
            address-family {
                l2vpn-evpn {
                    soft-reconfiguration {
                    }
                }
            }
            bfd {
            }
            remote-as internal
            update-source 10.0.0.254
        }
        system-as 65000
    }
}

PVE FRR (IP: 10.0.0.1)

!
frr version 10.2.1
frr defaults datacenter
hostname pve1
log syslog informational
no ip forwarding
no ipv6 forwarding
service integrated-vtysh-config
!
vrf vrf_pve
 vni 100
exit-vrf
!
router bgp 65000
 bgp router-id 10.0.0.1
 no bgp enforce-first-as
 no bgp hard-administrative-reset
 no bgp default ipv4-unicast
 coalesce-time 1000
 no bgp graceful-restart notification
 neighbor VTEP peer-group
 neighbor VTEP remote-as 65000
 neighbor VTEP bfd
 neighbor 1.1.1.1 peer-group VTEP
 neighbor 10.0.0.2 peer-group VTEP
 neighbor 10.0.0.3 peer-group VTEP
 neighbor 10.0.0.254 peer-group VTEP
 !
 address-family l2vpn evpn
  neighbor VTEP activate
  neighbor VTEP route-map MAP_VTEP_IN in
  neighbor VTEP route-map MAP_VTEP_OUT out
  advertise-all-vni
 exit-address-family
exit
!
router bgp 65000 vrf vrf_pve
 bgp router-id 10.0.0.1
 no bgp enforce-first-as
 no bgp hard-administrative-reset
 no bgp graceful-restart notification
 !
 address-family ipv4 unicast
  redistribute connected
 exit-address-family
 !
 address-family ipv6 unicast
  redistribute connected
 exit-address-family
 !
 address-family l2vpn evpn
  advertise ipv4 unicast
  advertise ipv6 unicast
 exit-address-family
exit
!
route-map MAP_VTEP_IN permit 1
exit
!
route-map MAP_VTEP_OUT permit 1
exit
!
end

Details

Version
2025.04.04-0018-rolling
Is it a breaking change?
Unspecified (possibly destroys the router)
Issue type
Bug (incorrect behavior)

Event Timeline

Viacheslav triaged this task as Normal priority.Apr 10 2025, 9:50 AM

It seems this is FRR issue.
after I removed update-source 10.0.0.254 in vyos, everything works again.

with update-source 10.0.0.254, BFD will enable multihop mode and mismatch Proxmox VE BFD mode.

some issue may be around this part.
https://github.com/FRRouting/frr/blob/stable/10.2/bgpd/bgp_bfd.c#L244-L267