> On 20. Apr 2020, at 04:02, Darren O'Connor <mellow.drif...@gmail.com> wrote:
>
> Is this an ipv6 route? nh length 32 means both a global and link-local
> address is being set. RFC2545 section 3
Yes, this is indeed an ipv6 route. I am using many IPv6 routes with other
peers, they do not hit the same code path. Thank you for the RFC pointer!
Cheers
Sebastian
> On Sun, 19 Apr 2020 at 21:39, Donald Sharp <sha...@cumulusnetworks.com> wrote:
> Sebastian -
>
> I cannot speak towards bird's behavior here but I can say that FRR has
> fixed a couple of nexthop related issues with what we send to our
> peers since the 6.0 release. I would please consider upgrading to a
> much later version if you can, 7.2 or 7.3 should have the fixes.
>
> thanks!
>
> donald
>
> On Sun, Apr 19, 2020 at 6:48 PM Sebastian Hahn
> <bird_us...@sebastianhahn.net> wrote:
> >
> > Hi,
> >
> > let me preface this that I very much do not know what I am doing here, and
> > have been somewhat unsuccessful in trying to understand what's going on by
> > searching online. I would love an explanation though!
> >
> > 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 b!
e !
> a !
> > rare configuration.
> >
> > I added this simple patch:
> >
> > --- bird2-2.0.7.orig/proto/bgp/packets.c
> > +++ bird2-2.0.7/proto/bgp/packets.c
> > @@ -1174,6 +1174,9 @@ bgp_decode_next_hop_ip(struct bgp_parse_
> >
> > if (ipa_is_ip4(nh[0]) || !ip6_is_link_local(nh[1]))
> > nh[1] = IPA_NONE;
> > +
> > + if (ip6_is_link_local(nh[1]))
> > + nh[0] = IPA_NONE;
> > }
> > else
> > bgp_parse_error(s, 9);
> > ~
> >
> > which worked for me to resolve the problem.
> >
> > Thanks for any consideration!
> >
> > Cheers
> > Sebastian
>
