Internal IP: The IP address assigned by the router to the device which
needs to be accessed remotely.
Internal Port: The internal port number of the device. You can enter a
specific port number. Leave it blank if it is same as the external port.
Enable: Enable of disable of the rule.
Open Ports on Router
The router's services, such as web and FTP, requires their respective ports
to be opened on the router in order to be publicly reachable.
To open a port, click Add.