Updated rc.firewall script for Honeynets using iptables.

[Rob McMillen <rvmcmil () cablespeed com>]

Finally, a combined firewall script for a Honeynet that can do both bridge 
and nat.  It's all in one file.  Simply change a couple of variables and 
you can have a containment system that acts like a bridge or a NATing firewall.

Please take some time to check it out, and feel free to provide comments, 
good or bad, to rvmcmil () cablespeed com.

The rc.firewall script can be found at:

        http://www.honeynet.org/papers/honeynet/tools/

Big changes:

- Allows addition of management interface.
- Restrict traffic to the management interface.
- Restrict connections originating from the firewall to those required.

But the main thing is that there is only one script to maintain.