After you installed the extension, you can do the following:
View and change the predefined rules that control connections to the following system services: Administrative control panel; Web server; FTP server; SSH server; SMTP server; POP3 server; IMAP server; mail password change service; MySQL server; PostgreSQL server; Samba file sharing server for Windows clients; VPN; domain name server; ICMP echo requests. By default, these rules allow all incoming connections to these services.
View and change the predefined system policies that define what to do with all incoming, outgoing, and transit communications that do not match the explicitly defined rules.
Add, change, and remove custom rules. For example, you may want to add a rule that will allow access to FTP accounts on the server in passive mode.