IPv6 routes not imported into Kernel

[Robert Finze]

Hi Gerdriaan,

I've followed your advice and set up 2 VMs for testing.


On 28.02.24 12:02, Gerdriaan Mulder wrote:
>> Next I want to try a fresh 20.04 install and see what happens.
> 
> I would try a fresh install of Ubuntu 20.04 with the same kernel as the 
> machine that currently works, indeed. If the problem goes away, it might 
> be an issue between Ubuntu 20.04 and 22.04. If the problem persists, it 
> might be some subtle configuration difference. I wouldn't yet upgrade to 
> BIRD 3.0alpha because that changes too many variables in order to debug 
> the problem.
A)
Ubuntu 24.04
Linux moon2 6.6.0-14-generic #14-Ubuntu SMP PREEMPT_DYNAMIC Thu Nov 30 
10:27:29 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
Bird 3.0alpha2
Bird 2.14
Bird 2.13

B)
Ubuntu 20.04
Linux moon3 5.4.0-172-generic #190-Ubuntu SMP Fri Feb 2 23:24:22 UTC 
2024 x86_64 x86_64 x86_64 GNU/Linux
Bird 2.14

C)
Ubuntu 20.04
Linux star 5.4.0-172-generic #190-Ubuntu SMP Fri Feb 2 23:24:22 UTC 2024 
x86_64 x86_64 x86_64 GNU/Linux
Bird 2.14

VM C is my current router which is working fine and from which I'm 
exporting one route towards A and B.

On VM A I've tested different bird version and all show the same 
behaviour. Before I've upgraded to 24.04 I've ran the tests on 22.04 and 
the results are the same.

VM C is exporting one route towards A and B which is being accepted by 
bird but on A doesn't end up in the kernel. On B there's no issues and 
everything is working as expected.
It seems that there is indeed a difference between 20.04 and 22.04 (and 
newer).
I'm a bit stuck here.

For now I'd be fine with running 20.04 on all routers, but eventually 
it'd be nice to upgrade.

> Besides, in your initial post, you pasted a few routes from BIRD that 
> were using protocols "upstream_1v6" and "upstream_2v6". They seem to be 
> missing from the bird.conf you posted. The route addition in the netlink 
> dump is different from the routes you showed in BIRD, which makes it 
> more difficult to pinpoint the problem.

Apologies for this. Yes, there are 2 more upstreams configured, but are 
shut so that it's easier to troubleshoot.

> I think it's a good idea to focus on getting just one route exported 
> from BIRD to the kernel successfully. If it's possible in your setup, 
> perhaps just configure 1 upstream, and only import 1 route from that 
> upstream in BIRD, and export the same route through the kernel protocol.
> 
> Best regards,
> Gerdriaan Mulder

Cheers,
Robert