Advices for a weird multihop setup

[Alarig Le Lay]

Hi,

I have a weird setup with a transit. My next-hop is 2a03:94e0:feff::
(with a multihop session) which is reachable via 2a03:94e0:17ff::1 which
is on-link on eno1. (your should already tear blood here)

So, when I establish the session, the next-hop couldn’t be resolved and
the route is marked as unreachable.
e.g.
2a00:9600::/47       unreachable [bgp_terrahost_ipv6 12:32:10.864 from
2a03:94e0:feff::] * (100/-) [AS25605i]
        Type: BGP univ
        BGP.origin: IGP
        BGP.as_path: 203629 6939 3356 25605
        BGP.next_hop: 2a03:94e0:feff::
        BGP.local_pref: 100

So, for now I’m just exporting route with a next-hop different of
2a03:94e0:feff:: and I added a default route (ip -6 r a default via
2a03:94e0:17ff::1 dev eno1 onlink) to a least do the necessary routing
on those.

 40 protocol kernel kernel_ipv6 {
 41         learn;
 42         persist;
 43         ipv6 {
 44                 import all;
 45                 export where bgp_next_hop != 2a03:94e0:feff::;
 46         };
 47 }

This seems to be a bit ugly for me, so I have to questions:
        * Is it possible to handle with on-link next-hop with bird?
        * I think not, so is there a less ugly work-around?

 75 protocol static static_terrahost_ipv6 {
 76         ipv6 {
 77                 import all;
 78         };
 80         route 2a03:94e0:feff::/128 recursive 2a03:94e0:17ff::1;
 81         route 2a03:94e0:17ff::1/128 via "eno1";
 82 }

257 protocol bgp bgp_terrahost_ipv6 from UPSTREAM_IPv6 {
258         description "terrahost";
259         neighbor 2a03:94e0:feff:: as 203629;
260         multihop 3;
261
262         ipv6 {
263                 import filter bgp_filter_terrahost_in_ipv6;
264         };
265 }

Regards,
-- 
Alarig