OS X Server: About the Firewall service
The Firewall service included in OS X Server (Mountain Lion) is not managed by Server app.
OS X Server (Mountain Lion)
The Firewall service was managed in Server Admin in Lion Server and Mac OS X Server v10.6. In Mountain Lion, the Firewall service is no longer controlled by OS X Server.
If you upgrade or migrate to OS X Server (Mountain Lion) from Lion Server or Mac OS X Server v10.6, your existing firewall rules will remain active in ipfw. If you don't want to keep using these Firewall rules, you can move them aside and disable ipfw with the following Terminal command:
sudo mv /etc/ipfilter /etc/ipfilter-old
The ipfw command is deprecated in Mountain Lion. If you want to manually configure Firewall rules, use the pfctl binary for forward compatibility. For instructions, see man pfctl.