repeating crashes with 8.1

[Ivan Voras]

On 10/21/10 21:08, Randy Bush wrote:
> FreeBSD 8.1-STABLE #2: Thu Oct 21 15:30:45 UTC 2010
>     root at rip.psg.com:/usr/obj/usr/src/sys/RIP amd64
> 
> console recording
> 
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> em0: discard frame w/o packet header
> panic: sbflush_internal: cc 4294965301 || mb 0 || mbcnt 0
> cpuid = 0
> panic: bufwrite: buffer is not busy???

What does the machine do? Does it perhaps have 6to4 (stf) enabled?