If you’re an IT Administrator, there have probably been times when you wish you could map a specific port on one computer to another port on a different machine, right?
For example, let’s say you have a proxy server running and would like to access other machines through the proxy. If you want to access a server running FTP, it would be nice to just configure the proxy to forward all traffic from port 21 to the appropriate machine.
Port Mapper is a nifty utility that you can use to forward TCP and UDP ports from one machine to another. So if you want to map one port to another port on a different IP address, definitely check out this program.
You can use it for other services like remote desktop. By default, if you want to remotely access multiple computers on a single network using remote desktop, you have change the RDP listening port from the default 3389. Read my post here on how to setup remote desktop.
Using Port Mapper, you can tell your main server to forward 3389 to one IP address on the internal network, 3390 to another, and so on. This would be an alternate method to configuring these options on your router or firewall.
Once Port Mapper starts up, it loads in the Windows taskbar. You have to right-click on the icon and choose Configure to add new entries.
Once you choose Configure, you’ll have the option to Configure IP or Configure Mapping. We’ll talk about the other one in a minute.
First click on Configure Mapping and now click on the Add button. Now you can enter the local port you want to forward and the IP address or DNS name of computer you want to forward the data to. Choose the protocol and which interface.
Click OK and now you’ll see the port mapping in the list. You can continue adding as many port mappings as you like.
That’s it for mappings! If you click on the Configure IP button, you can block or allow certain IP addresses from connecting to your computer/server. If you’re running a home web server and only want your friends to be able to connect, you can allow only certain IPs and all the rest will be blocked.
Same thing if you’re running your own FTP server and you want to prevent people from connecting who are not authorized. This will add an extra level of security.
So there you have it, a simple and effective way to map ports and to block IP addresses from connecting to a machine. Enjoy!
Port Mapper supports IP:port syntax on a target, so you don’t have to change RDP configuration on remotes.