To set Port Mapping
Select the protocol used by application/service. Some applications/services use TCP and UDP protocol together.
Listen IP
The IP address the incoming requests are coming to. Usually it is the IP address associated with your Internet interface. Note: you may have more than one IP address associated with the Interface (if you have more web servers etc.) In most cases you will leave this option unspecified, especially if you receive your IP address dynamically.
Listen Port
The port number that requests will be coming to (e.g. 80 for http).
Destination IP
The IP address within your local network that is running the server (service) answering incoming requests (web server, FTP server etc.)
Destination Port
The port that the destination application is listening on. Typically the same number as the listen port
Allow access only from
You may reference a pre-defined address group so that the port will only be open to the IP addresses included in that address group. The address groups are defined in the advanced settings.