Raymond.CC Blog

Port forwarding is the act of forwarding a network port from one network node to another. This technique can allow an external user to reach a port on a private IP address (inside a LAN) from the outside via a NAT-enabled router. Port forwarding allows remote computers (e.g. public machines on the Internet) to connect to a specific computer within a private LAN. UPnP technology makes port forwarding easy by automatically forwarding the port required. However, for UPnP to work, both the program and router must support UPnP.

If you don’t have a router that supports UPnP and don’t know how to forward ports on your router, a program that requires port forwarding will either don’t function fully or at all! Some of that softwares that requires port forwarding to perform at peak levels are Limewire and uTorrent. You’ll notice a huge increase in download speed once you’ve forwarded the port.

I found a free program that is able to automatically detect ports opened by applications running in your system and map them to your router. This is very useful for those people who don’t know anything about port forwarding or don’t dare to mess around with their router configurations.


Port Mapper is a lightweight Windows application that securely manages the ports on your Home Networking Router. It effectively cuts down on the time spent by you in configuring and monitoring your home router. It works to automatically map the ports opened to the router while you are still playing a game or running any web-based application.

Port Mapper runs in your task bar and prompts whenever a new port is opened by some application.When a port is opened by an application so as to communicate with the internet, Port Mapper will popup a window at the bottom right corner and ask whether you would like to to forward the port. If you say yes, Port Mapper will automatically forward the port, and configure your Router to allow internet users to to communicate with the application.

Installing and using PortMapper is easy. Just download, extract and run PortMapper.exe. When running for the first time, you’ll see a Welcome Screen. The most important information is to enter your Router Username and Password for Port Mapper to check your Router settings, and forward ports.

To uninstall, just run Uninstall.bat from the PortMapper directory.

Other than forwarding ports, PortMapper can also act as a basic firewall. Some trojans that is able to remote access your computer requires port forwarding. Let’s say the legendary Subseven trojan thats already planted on your computer and requires to forward port 1243, PortMapper will detect and alert you. Other than that, most of the time we don’t remember to close the port when we’re not using it and will remain open to the Internet and to security threats. But I’d advice you not to use PortMapper as your firewall application because there are many ways a hacker can get in your computer.

PortMapper is VERY useful but unfortunately currently it can only support very few routers listed below. If your router is not listed below, you can request your router to be supported by submitting a form here.

Linksys Routers
BEFSR41, BEFSR81, BEFSX41, BEFVP41, BEFW11S4, WAG54G, WRT54G

D-Link Routers
DI-624, DI-524

Netgear Routers
MR814

[ Download HomeNetMagic PortMapper ]