Open Ports is used to forward series ports to a single server in your LAN. In our example it will be an email server that is configured for POP mail. We will use the Vigor2820 router in our example where the Open Ports facility provides 20 entries for internal hosts
Go to “NAT>>Open Ports” and select the first index and enter the details as shown below. You can edit the entries by clicking the index numbers. The email server has the IP address 192.168.1.10 in our example :
Comment option is used to display the name for the specified network service and you can select the IP of your internal Server/PC by clicking the ‘Choose PC’ button. Then you can specify which TCP/UDP ports you want to forward to this Server/PC.