nd6_lookup prints bogus messages with point to point devices

[Bruce A. Mah]

If memory serves me right, Ed Schouten wrote:

> On one of the FreeBSD machines we maintain at Dispuut Interlink[1], we
> get a lot of messages like these:
> 
> | nd6_lookup: failed to add route for a neighbor(<ipv6-addr>), errno=17
> 
> The addresses mentioned in the messages are all addresses of endpoint
> addresses of point-to-point devices. The nd6_lookup() call in the
> function nd6_output() is responsible for it. If you look through
> nd6_output(), you see that a couple of lines below the nd6_lookup() call
> it doesn't really care when dealing with IFF_POINTOPOINT devices.
> 
> It would be really useful to drop the messages when dealing with point
> to point devices, so I write a patch[2] for nd6_lookup() to make it
> print the message when not dealing with IFF_POINTOPOINT devices.
> 
> Should I open a PR for this patch?

I think that suz@ and ume@ are the people who have worked in this area
most recently, hopefully one of them will speak up.  You didn't give a
lot of details...please give (at a minimum) the version of FreeBSD
you're using and more details about the interface over which you're
having this problem.

I saw this on RELENG_6 sometime after some IPv6 ND changes that were
merged in late last year.  I have a gif(4) tunnel to my ISP over which I
do IPv6.  The GIF tunnel was originally configured as a point-to-point
interface and I got the same messages you mentioned.  My workaround was
to configure the gif(4) interface as a /127, which was obviously only
possible because the two interface addresses on each end of the tunnel
just happened to differ only in their least-significant bits.  (I know
this isn't the right solution.)

Bruce.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 249 bytes
Desc: OpenPGP digital signature
Url : http://lists.freebsd.org/pipermail/freebsd-net/attachments/20060508/7b8b97f1/signature.pgp