internet gateway

[Brett Wiggins]

Hi,
   I am having some problems setting up an internet gateway for my home network. My gateway machine has two network cards, one connected to my ADSL modem and the other to a switch and my internal network. My gateway machine (FreeBSD) can connect to the internet and it can ping machines on my local network. Machines on my local network run windows.

     ISP
      |
      | 
     ADSL
     MODEM
      |
      |
    FREEBSD           |----- MACHINE A
    MACHINE           |
      |               |
      |-------SWITCH--|----- MACHINE B
                      | 
                      |
                      |----- MACHINE C

So Far I have recompiled my kernel with the following options added;
   options IPFIREWALL
   options IPDIVERT
   options IPFIREWALL_VERBOSE
   options IPFIREWALL_VERBOSE_LIMIT=50
   options TCP_DROP_SYNFIN

I then edited /etc/rc.conf
   gateway_enable="YES"
   firewall_enable="YES"
   firewall_script="/etc/rc.firewall"
   firewall_type="OPEN"
   firewall_quiet="NO"
   ppp_enable="YES"
   ppp_mode="ddial"
   ppp_nat="YES"
   ppp_profile="netspace"
   ifconfig_rl0="inet 10.0.0.1"

Then I edited ppp.conf with the following;
   nat enable yes
   nat log yes
   nat same_ports yes
   nat unregistered_only yes
   enable dns

That is where I got up to now i'm stuck and don't know what to do next. Any help with this would be great.

Brett