UPnP is a convenient way for programs to forward ports without you having to pull up your router’s web interface and forward ports manually. Unfortunately, some programs that require port forwarding don’t support UPnP – that’s where UPnP PortMapper comes in.

This application takes care of port forwarding for you, right from your desktop. If your IP address changes, you don’t need to log into your router and change your port forwarding rules – you can have the application update them for you.

If you visit a friend’s house and join their network, you don’t have to ask for their router’s password to forward ports – just fire up the application and activate your preset rules.


UPnP Port Mapper is written in Java, so you’ll need the free Java Runtime Environment (download from Ninite) installed to run it. After installing Java, you can download UPnP Port Mapper from SourceForge. In addition to Windows, this application also works on Mac OS X and Linux.

UPnP Port Mapper communicates with your router with the UPnP protocol, so you’ll also need a router with UPnP enabled to use this application. If UPnP is disabled on your network’s router, this program can’t do anything.

After downloading UPnP Port Mapper, double-click the .jar file to launch it.

Forwarding Ports

To get started, click the Connect button in UPnP Port Mapper. If you see a Windows Firewall pop-up window, click the Unblock button. You may have to allow Java network access in the Windows firewall pop-up that appears.

If UPnP PortMapper informs you that it can’t find your router, click the Connect button again unblocking the application in the Windows firewall.

If it worked, you’ll see a list of UPnP port mappings in the top pane (this list will be empty by default), as well as your router’s external IP address on the Internet and its IP address on your local network.

To create a new port forwarding preset, click the Create button.

Enter a description for your port forwarding rule and provide a list of one or more ports to forward. You can specify port ranges or forward a list of ports using a single preset.

You can also specify a specific remote host. If you enter an IP address, only traffic from that IP address will be forwarded to your computer from your router. For example, you can use this feature to only allow connections from a friend’s IP address on the Internet.

The Use local host box is checked by default, making it easy to forward ports without having to double-check your computer’s local IP address. However, you could also use this application to forward ports to multiple different computers on your network.

Port forwarding presets you specify will appear  in the Port mapping presets box. Select a preset and click the Use button to activate it.

Clicking this button forwards the ports on your router – they’ll appear in the Port mappings box at the top of the window. You can remove port mappings by selecting them and clicking the Remove button.

The port mappings will be saved on your router until its UPnP data is cleared – depending on your router, this may happen when your router is restarted. If you open UPnP Port Mapper later and click the Connect button, you’ll see your active port mappings.

You will also need to reapply port mapping settings if your computer’s local IP address changes.

With your presets, you can quickly and easily apply these port mapping settings on any network with a router that supports UPnP – this can be convenient if you move around and need to forward ports for gaming, servers, or other purposes.

Profile Photo for Chris Hoffman Chris Hoffman
Chris Hoffman is Editor-in-Chief of How-To Geek. He's written about technology for over a decade and was a PCWorld columnist for two years. Chris has written for The New York Times and Reader's Digest, been interviewed as a technology expert on TV stations like Miami's NBC 6, and had his work covered by news outlets like the BBC. Since 2011, Chris has written over 2,000 articles that have been read more than one billion times---and that's just here at How-To Geek.
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