FRR 8.4.2 doesn't advertise APIA 169.254/16 on L3VPN

[networking-hub]

Hello,

I'm working on a network issue (that is quite weird actually). I have a FRR connected to a physical PE, isis/bgp/mpls/mp-bgp ... everything working fine except :

• While setting a 169.254.0.20/32 (for example) on a loopback attached to a VRF, this prefix is not advertised and as consequence is not reachable by other PEs or CPE on the same VRF.

I'm getting these debug messages :

**2023-02-17 16:07:18.214 [DEBG] zebra: [J3J81-V75NW] Route rtm_type: anycast(4) intentionally ignoring
....
2023-02-17 16:58:56.751 [DEBG] ldpd: msg[out]: address withdraw: lsr-id 10.16.168.161, address 169.254.0.20
2023-02-17 16:58:56.751 [DEBG] ldpd: msg[out]: address withdraw: lsr-id 10.16.168.161, address 169.254.0.31
......**

Here is the loopback configuration :

**interface loopback84189
 ip address 169.254.0.20/32
 ip address 169.254.0.31/32
exit**

And of course these prefixes are not visible in bgp routing table :

BGP table version is 35, local router ID is 169.254.0.20, vrf id 8
Status codes:  s suppressed, d damped, h history, * valid, > best, = multipath,
               i internal, r RIB-failure, S Stale, R Removed
Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self
Origin codes:  i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

   Network          Next Hop            Metric LocPrf Weight Path
*> 0.0.0.0/0        10.16.168.245@0<
                                                  500      0 65001  i
... some public prefixes ...
*> 169.254.0.0/31   10.16.168.245@0<
                                             0    100      0 ?
*> 169.254.0.2/31   10.16.168.158@0<
                                             0    100      0 ?
*> 169.254.0.4/31   10.16.168.163@0<
                                             0    100      0 ?
*> 169.254.0.8/31   10.16.168.179@0<
                                             0    100      0 ?
*> 169.254.0.13/32  10.16.168.116@0<
                                             0    100      0 ?
*> 169.254.0.255/32 10.16.168.218@0<
                                             0    100      0 ?
*> 172.16.0.4/30    10.16.168.179@0<
                                             0    100      0 ?
*> 192.168.252.6/32 10.16.168.179@0<
                                             0    100      0 ?

When i change the ipv4 address and put (192.168.x.y/32) everything works fine...

Anyone knows why is it behaving this way ?

Thanks

[donaldsharp]

169.254.0.0/16 according to RFC's is link local and as such cannot be disseminated in bgp. We enforce it