This is what I do. You have eth0 setup. On eth1 make sure to only set the IP and netmask. Do not set a gateway on eth1.
Now goto http://easyfwgen.morizot.net/gen/
and answer the questions it ask to setup a firewall/router gateway. This generates a script that is displayed in the browser. Cut and paste the text of the script shown and save to a file called firewall.sh. Put the file in /etc. Set the script to have the execute attribute. ' /sbin/shmod + /etc/firewall.sh '.
Turn off current Fedora Firewall and disable it from boot.
/sbin/service iptables stop
/sbin/chkconfig --level 345 iptables off
Now goto /etc and run the script likethis' ./firewall.sh '. Got a lan machine and test internet. Then goto say http://www.hackerwatch.org/probe/
and test for open ports. This can be done from any machine on the network.
Thats it. Done a few this way for years.
Distribution: RHEL 5.1 with Pieces of this and that.
Kernel 18.104.22.168, KDE 3.5.8 and KDE 4.0 beta, Plus Development src.rpm, ATI fglrx64_7_1_0-8.433-1 rpm with 3D and DRI working.
Acer 5100-5840 with webcam, ati, sdcard reader, sound, atheros based wireless, all working. Only thing not working is the memory stick reader.