ipv6 and magically vanishing routes via gif0

[Motoyuki Konno]

Hi,

I had the same problem on my FreeBSD 6-STABLE box.
Fix was already committed to -current (src/sys/netinet6/nd6.c
rev 1.69), but not yet to 6-STABLE.

Try src/sys/netinet6/nd6.c rev 1.48.2.13 (older version)
instead of 1.48.2.14.

--
motoyuki

Stefan `Sec` Zehl <sec at 42.org> wrote:
> Hi,
> 
> I just upgraded from FreeBSD-5 to -6, and now my default route via gif0
> vanishes after 7 seconds.
> 
> | ice:~#ifconfig gif0
> | gif0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1280
> |         tunnel inet 194.77.85.2 --> 193.149.44.208
> |         inet6 fe80::20e:a6ff:fe04:ea37%gif0 prefixlen 64 scopeid 0x14
> |         inet6 2001:608:9::1 prefixlen 128
> | 
> | ice:~#route add -inet6 default -interface gif0
> | add net default: gateway gif0
[snip]
> In fact, any route '-interface gif0' will vanish 7 seconds after the
> first packet via that link.
> 
> After some wild guesses, I found out, that ndp seems to be the culprit
> here. -- If I disable ndp on gif0 with 
> 
> | ice:~#ndp -i gif0 -- -nud
> | linkmtu=0, maxmtu=1280, curhlim=64, basereachable=30s0ms, reachable=18s, re
trans=1s0ms
> | Flags: accept_rtadv
> 
> Then the routing table stays as it should.
> 
> The question is, am I missing something here? Can anybody reproduce that
> problem?
> 
> It seems wrong that the kernel would delete static routes without even a
> single log message.  Furthermore I find it kind of strange that there is
> neighbour discovery happening at all on an tunnel interface.