I am attempting to set up my firewall using firestarter, but I have ran into an problem. Whenever I finish going through the wizard and try to start the firewall I get a message that says:

Failed to start the firewall
the device eth0 is not ready

I opened up my networking tool and found that my connection is coming through a device labeled loopback interface(lo). That doesn't show up on firestarter though. Whenever I look through possible devices all I find are eth0, wifi0, and ath0. Does anyone have any ideas about what may be going on.

Sounds like your eth0 interface isn't enabled. 'ifconfig' will show all enabled devices. 'ifconfig -a' will show ALL NICs, regardless of status.

Enable your eth0. 'lo' isn't the proper network interface that you need. You can either enable it by statically assigning an IP and running 'ifconfig eth0 up' or by telling your DHCP client to get an IP and assign it to eth0.