wierd router crashes...

[Alison Lloyd]

Hiya

I'm trying to get a FreeBSD box set up as a router between my cable
internet connection and my home LAN.  I'm using a Compaq Professional
Workstation 5000 (yes, the Pentium Pro thingy), which I've installed an
extra NIC into.  The output from uname -a is:

FreeBSD gorgonzola 4.9-RELEASE FreeBSD 4.9-RELEASE #1: Thu May 20 23:35:28
BST 2004 root at gorgonzola:/usr/obj/usr/src/sys/GORGONZOLA i386

I'm using 4.9 because 5.2.1 refuses to find any harddrives (IDE or SCSI),
incidently.  I've recompiled the original kernel to include ipfw support. 
My firewall ruleset is:

add 10000 divert 8668 ip from any to any via tl0
add 60000 allow ip from any to any
add 11010 allow tcp from any to any established
add 11100 deny log tcp from any to tl0

where tl0 is the external interface and rl0 is the internal one.  I've got
everything up and running, got the external interface registered with my
ISP, and can connect to the internet fine (http, ftp, ports all work). 
I've set the box up to DHCP for its external IP (which it does fine), and
to use 192.168.1.1 for the internal one.

The problems come in when I try to use a machine on the internal LAN - the
router locks solid - no response to anything at all.  It passes a few
packets to start with, but then dies.  After reboot, there are no
suspicious entries in the logs, at least none that I can find.  So long as
I don't do anything on the internal LAN, everything runs perfectly!

I've tried disabling all extraneous things (sendmail, etc.), to no avail. 
I'm not sure what to try next, as I'm fairly new to FreeBSD and firewalls
/ routers in general.

Heeeeeeeelp!
  Alison