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

[Alexander Zubkov]

Hi Lucas,

"protocol device" might be an issue, I think it's almost must-have for bgp.
Because to establish the session bird needs to know interfaces and ip
information. And that is supplied by "protocol device".
https://bird.nic.cz/doc/bird-3.2.0.html#device

Regards,
Alexander

On Thu, Mar 26, 2026 at 10:10 PM Lucas da Vila <dev at ldv.ar> wrote:

> Hi Alexander,
>
> I don't have a "protocol device" I was just hoping to receive the
> announcements from the RR a get the BMP output for analysis.
>
> Regards
> lucas
>
>
> On Thu, Mar 26, 2026, 16:46 Alexander Zubkov <green at qrator.net> wrote:
>
>> 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/ce3402f8/attachment.htm>