> On 20. Apr 2020, at 05:05, Ondrej Zajicek <santi...@crfreenet.org> wrote:
> On Mon, Apr 20, 2020 at 12:46:17AM +0200, Sebastian Hahn wrote:
>> In a bird 2.0.7 setup, I was unable to import routes from one of my peers.
>> It is the only one using frr (version 6.02-2 on debian), most other peers
>> use bird1 or bird2. I noticed immediately after adding the peering that I
>> received "Invalid NEXT_HOP attribute" errors in the log. Unfortunately, no
>> more information than that was provided in the log, so I went on a little
>> hunt. Since the exact error is raised from many places, I added some logs to
>> identify the GW_DIRECT case in bgp_apply_next_hop() as the culprit. Here I
>> realized that both gw and ll are set, which means a neighbor is tried to be
>> found which doesn't involve the ll case. I then noticed that in
>> bgp_decode_next_hop_ip(), this can only happen if len == 32. This is where I
>> am absolutely clueless what it means for the nh len to be 32, and thus I
>> don't know if the patch I came up with is correct, even though it works for
>> my testing. Only this one peer using frr causes nh len to be set to 32, so I
>> suppose it might be!
a !
>> rare configuration.
>
> What is your BIRD config? It seems that most likely BIRD cannot resolve
> the global next hop IP address (the on in gw). Because it is GW_DIRECT,
> it is resolved only in local addresses.
Hi,
and thanks for the responses. Here is the config:
protocol bgp v6_frr_peer {
local as <myas>;
direct;
neighbor fe80::1 as <theiras>;
interface "frr_peer";
ipv6 {
import keep filtered;
import filter import_filter;
export filter export_filter;
};
}
I use fe80::42, the peer uses fe80::1 on this link.
Please let me know if I can provide more information in any way.
Thanks
Sebastian
