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

[Alexander Zubkov]

Hi Lucas,

I have some working bgp sessions over link-local addresses. Only that they
are hand-configured, not automatic ones. And I have bird2, not bird3. My
config is something like this:

protocol bgp bgp_router_c6 {
        neighbor fe80::2 as 65000;
        local fe80::1 as 65000;
        interface "vlan100";
        direct;
        strict bind yes;
        free bind yes;

        ipv6 {
                next hop keep; ...
        };
}

"free bind" should not be necessary here, I think. Do you have "protocol
device" in your config?

Regards,
Alexander Zubkov

On Thu, Mar 26, 2026 at 8:21 PM Lucas da Vila <dev at ldv.ar> wrote:

> 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
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://trubka.network.cz/pipermail/bird-users/attachments/20260326/dc00878f/attachment.htm>