kern/107358: IPv6 6to4 broken in FreeBSD 6.1-RELEASE-p11

[Antonio Querubin]

>Number:         107358
>Category:       kern
>Synopsis:       IPv6 6to4 broken in FreeBSD 6.1-RELEASE-p11
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Dec 30 19:00:32 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Antonio Querubin
>Release:        FreeBSD 6.1-RELEASE-p11 i386
>Organization:
LavaNet
>Environment:
System: FreeBSD localhost 6.1-RELEASE-p11 FreeBSD 6.1-RELEASE-p11 #0: Mon Dec 18 05:01:40 HST 2006 root at localhost:/usr/obj/usr/src/sys/GENERIC i386
>Description:
IPv6 6to4 broke somewhere between 6.1-p2 and 6.1-p11.  This effectively disables IPv6 connectivity for hosts on non-native IPv6 networks.

>How-To-Repeat:
Using a system on a network which has no native IPv6 connectivity:

In /etc/rc.conf:

  - Enable IPv6.
  - Configure stf_interface_ipv4addr with the local IPv4 address.
  - Set ipv6_defaultrouter to the standard RFC 3068 address 2002:c058:6301::

Boot generic kernel 6.1-p11.

Verify the stf0 interface is up and configured with a 6to4 address.

ping6 the stf0 IPv6 address and you get no response.

ping6 or traceroute6 to any outside IPv6 host (eg. www.isc.org) and you get no response.

>Fix:
Boot generic kernel 6.1-p2 and repeat above tests.  You should get ping responses from the local stf0 address as well as outside IPv6 hosts.

I suspect this broke beginning in p5 and any kernel prior to p5 will also work.

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