noah is right, let me modify the configuration so that you can use real
IP and masq_ip as well:
ROUTER-------- Linux ------
| |
| | Internal_IP
| |
---------- ----------------
| HUB 2 | | HUB |
__________ ----------------
|||||||||| | | | | | | | |
Yes, you need another other hub, but you need one less network card.
Many people use this arch. for home LAN.
I could show you the ipchains rules for your reference but only upon
your request.