System information

Connection Tracking Setup
Connection tracking setup is required for NAT. If you use NAT, you'll need to enable this, and you'll
want to review which protocol helpers are enabled. If you don't enable the protocol helpers for these
particular protocols, you'll find those protocols won't work properly for NATed clients.
The FTP helper is for active FTP sessions. Passive FTP session (such as those set up by most web
browsers) will work just fine.
The IRC helper is for Internet Relay Chat.
The H323 helper is for those phones and programs (like Netmeeting) that use H323. Phones that use
the SIP or IAX protocols are unaffected by this setting
The GRE (Generic Routing Encapsulation) protocol helper is used if you use GRE. Those working in
Cisco environments may need to enable this.
The PPTP NAT helper enables point-to-point tunneling protocol help.
fig 5: Connection tracking table setup