kern/160206: gifX stops working after a while (IPv6 tunnel)

[Martin Laabs]

>Number:         160206
>Category:       kern
>Synopsis:       gifX stops working after a while (IPv6 tunnel)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Aug 26 11:10:06 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Martin Laabs
>Release:        8.2-STABLE
>Organization:
-
>Environment:
FreeBSD server.martinlaabs.de 8.2-STABLE FreeBSD 8.2-STABLE #1: Fri Apr  8 15:35:37 CEST 2011     martin at server.martinlaabs.de:/usr/obj/usr/src/sys/SERVER_KERNEL  i386

>Description:
I have the sixxs-aiccu port running that creates a IPv6 tunnel to get IPv6 access. This is working fine but sometimes the gifX interface stucks so it does not work anymore. It doesn't even answer to a ping6 to its local adress.

Restarting the sixxs-aiccu daemon (that recreate the gifX interface for me), destroying and recreating the gifX interface afterwards and even using an other gifX interface (i.e. gif1 instead of gif0) do not resolve the problem.

Rebooting the whole system however restore the IPv6 connectivity.

The routing table is also OK and no special ipfw filters are configured.

# ifconfig gif1
gif1: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> metric 0 mtu 1280
        tunnel inet 192.168.1.250 --> 212.224.0.189
        inet6 fe80::230:5ff:fe69:c309%gif1 prefixlen 64 scopeid 0x5 
        inet6 2001:6f8:1c00:1b8::2 --> 2001:6f8:1c00:1b8::1 prefixlen 128 
        nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
        options=1<ACCEPT_REV_ETHIP_VER>

# ping6 -c5 2001:6f8:1c00:1b8::2
PING6(56=40+8+8 bytes) 2001:6f8:1c00:1b8::2 --> 2001:6f8:1c00:1b8::2

--- 2001:6f8:1c00:1b8::2 ping6 statistics ---
5 packets transmitted, 0 packets received, 100.0% packet loss

# netstat -nr
[...]
Internet6:
Destination                       Gateway                       Flags      Netif Expire
::/96                             ::1                           UGRS        lo0 =>
default                           2001:6f8:1c00:1b8::1          UGS        gif1
::1                               ::1                           UH          lo0
::ffff:0.0.0.0/96                 ::1                           UGRS        lo0
2001:6f8:1c00:1b8::1              2001:6f8:1c00:1b8::2          UH         gif1
[...]


>How-To-Repeat:
Don't know how to repeat the problem reproducible
>Fix:
Reboot the whole system

>Release-Note:
>Audit-Trail:
>Unformatted: