Recursive nexthop via kernel route in proto static not working

[Alexander Zubkov]

Hi,

Not sure, but I would guess it can be related to the local address. It
might try to pick the first interface with such network. Could you try
your setup with some route that has the nexthop from a unique subnet
configured on the interface? At least to check if it will become
reachable or not.
Or it might be that routes imported from the kernel are marked as
recursive, so it does not resolve because Bird does not allow double
recursion.

On Tue, Jun 27, 2023 at 4:22 PM Daniel Gröber <dxld at darkboxed.org> wrote:
>
> Hi,
>
> I'm trying to configure a static route that uses the system's default
> router. The default router is out of my control and is announced via IPv6
> RA. Since the MAC might not be stable I'd prefer not to hardcode the
> router's link-local address. So I tried:
>
>     protocol static static_export_kernel2 {
>         ipv6;
>         igp table master6;
>         route 2001:db8::/48 recursive ::;
>     }
>
> The thinking being that :: ought to be resolvable through the default route
> imported from proto kernel:
>
>     birdc show route for :: all
>     Table master6:
>     ::/0                 unicast [kernel1 2023-03-22] * (10)
>             via fe80::fc00:3ff:fec7:cd05 on enp1s0
>             Type: inherit univ
>             Kernel.source: 9
>             Kernel.metric: 1024
>             Kernel.hoplimit: 64
>
> However the static route ends up being "unreachable":
>
>     2a0d:f302:114::/48   unreachable [static_export_kernel2 13:59:32.819] * (200)
>             Type: static univ
>
> Any ideas why this isn't working?
>
> Thanks,
> --Daniel
>
> PS: The reason I have to create this static route when it's already covered
> by the default route has to do with an esoteric policy routing setup and
> multiple routing daemons ask for details at your own peril :)