Network with SUSE firewall2

Hi I have two boxes both running 9.0. I have an ADSL connection to the main box connected via NIC eth0. I have another NIC on eth1. The scond box has an NIC on ethO. I can ping each machine successfully. What I want to do is share the internet connection between the two. I have looked at the yast options to configure SUSE firewall2 but am not sure which ones to choose. I'd be grateful for a quick help guide. TIA Mike