FreeBSD current nat/ppp/ip_output bug

[Sperber]

http rquests over lan caused a kernel trap 12 on my freebsd machine with 
current from 16.02.04 and 17.02.04.
it stops at ip_output+0x9a4: movl 0x98 (%esi),%eax
i use ppp -nat combined with isdnd (if you need more of the trap msg please 
tell me)
accidentially i did not trace it...

 Regards,
  Sperber

(i also can give you the cvs update list between the version which works and 
the the version which crashs)