acl-gen.
Build a firewall rule once and see the equivalent Cisco IOS ACL, pfSense rule, and iptables command, side by side.

Add a rule

Rule set

Rules are checked in order from top to bottom. On real devices, the first matching rule wins and the rest are skipped, so a broad allow or deny placed too early can silently override rules below it. Use the up and down buttons to reorder.