I’ve tried fwbuilder some times and never really liked it.
What I do with the multiple subnetting vpn, etc, on zeroshell is:
.- Direct the traffic from that interface to the particular chain I created. i.e. “-i ppp+ ” to chaing pptp traffic, and so on …
.- Use a LOT the “-m comment –comment” so I can document all the rules.
With this simple stuff, you can manage hundreds of rules without more problems than you’ve in fwbuilder.
The only thing, I wish that zeroshell could have more power when editing rules, like moving the rules up and down, or being able to copy a rule (like pfsense does), then it would be perfect