kern/106400: fatal trap 12 at restart of PF with ALTQ if ng0 device has detached

[Volker]

The following reply was made to PR kern/106400; it has been noted by GNATS.

From: Volker <volker at vwsoft.com>
To: bug-followup at FreeBSD.org,  bst2006 at dva.dyndns.org
Cc:  
Subject: Re: kern/106400: fatal trap 12 at restart of PF with ALTQ if ng0
 device has detached
Date: Wed, 06 Dec 2006 14:16:42 +0100

 First I would suggest to use ALTQ w/ mpd not on ng0 but on the real
 physical interface (for example fxp0, xl0) which is being used by
 netgraph/mpd.
 
 On the other side I also do have trouble using ALTQ with mpd but I'm
 using mpd for a 3G connection (based on a tty device, not a NIC).
 
 Avoiding ALTQ rules in pf.conf for the ng0 interface (not using ALTQ
 on ng0) doesn't produce a fatal trap 12. So disabling ALTQ in your
 kernel is not the only workaround. You may still use ALTQ on your
 internal NIC without a trap.
 
 Unlike your experience, I always do experience a kernel trap when
 reloading pf rules w/ ALTQ on ng0 (whether or not pf rules are
 reloaded by a script or manually).
 
 This also occours while the ng0 interface is still there and from my
 experience it's not related to a reload of mpd.