Bug in netgraph?

[Sebastiaan van Erk]

Hi,

There seems to be a bug/problem with GRE (netgraph) in FreeBSD in 
dealing with fragmented packets. When I have the following nat rules:

List of active MAP/Redirect filters:
map ng0 10.0.0.0/8 -> 80.126.244.3/32 portmap tcp/udp 40000:50000 
mssclamp 60
map ng0 10.0.0.0/8 -> 80.126.244.3/32 mssclamp 60

everything works, but when I don't include the mssclamp option then 
connects to for example www.google.com (searching for test) from my 
internal network hang and timeout constantly.

I'm using FreeBSD 6.0 stable in combination with mpd and ipfilter 4.1.18:

IP Filter: v4.1.8 initialized.  Default = block all, Logging = enabled

sebster at piglet(ttyp8:16:64):~> mpd --version
Version 3.18 (root at piglet.sebster.com 22:28  5-Nov-2005)

sebster at piglet(ttyp8:12:0):~> uname -a
FreeBSD piglet.sebster.com 6.0-STABLE FreeBSD 6.0-STABLE #12: Wed Nov 16 
13:34:20 CET 2005 
root at piglet.sebster.com:/usr/obj/usr/src/sys/PIGLET  i386

Greetings,
Sebastiaan van Erk