natportmapper provides a web UI to help system administrators to map NAT network internal and external ports easily. You can easily manage your NAT network without knowledge on network.
1.Download source code from natportmapper project download page.
2.Enable linux kernel ip forwarding.
3.Remember to change sudo configuration file.
Feel not that distinct? Please look at following screenshot.
After click submit button, you will see the nat port mapping is done. following pic shows how: