Subject: Bird3 - Establishing a BGP session over IPv6 LL addresses

26 Mar 2026

      Hi!

I'm a member of the DN42 network, and I have a mikrotik router connected to
it, I've only have 1 peer and I'm receiving over MP-BGP IPv4 and IPv6
prefixes. Also on the mikrotik I'm running a route-reflector.

With my bird3 (3.2.0 from debian repo) instance I'm trying to connect to
the route reflector over a couple of IPv6 LL addresses. But it doesn't seem
to be working. This is my bird3 config:

```
router id 192.168.1.200;

log "/var/log/bird/bird.log" all;

protocol bgp mkt01_dn42_rr {
        description "mkt01 dn42 RR";
        # local 192.168.1.200 as 64512;
        local fe80::42e2:30ff:fe60:edbb%wlp2s0 as 64512;
        # neighbor 192.168.1.201 as 64512;
        neighbor fe80::2805%wlp2s0 as 64512;

        interface "wlp2s0";
        direct;
        strict bind yes;

        ipv4 {
                import all;
        };

        ipv6 {
                import all;
        };

}

protocol bmp {
        station address ip 127.0.0.1 port 5000;
        monitoring rib in pre_policy;
        monitoring rib in post_policy;
}
```

After trying adding and removing params liks strict bind, interface, etc I
was not able to land a configuration that finally worked.

I must say that over IPv4 the session was established, but over IPv6 stills
in Idle.

Is anyone out there with a similar config? Any ideas why this happens?

Regards,
Lucas

Subject: Bird3 - Establishing a BGP session over IPv6 LL addresses

Lucas da Vila