Are you running a webserver or some other type of server, and want to limit who can access it by IP address? Or perhaps you're running AnalogX Proxy, and would like to route some special data types as well. In either case, AnalogX PortMapper is a great addition to your Internet toolbox.

AnalogX PortMapper is very easy to configure; there are basically two components to the program - the ability to block access based on IP ranges, and the ability to forward TCP or UDP packets.

The port mapping in AnalogX PortMapper is pretty straight-forward; simply select the port you want to listen on, choose from TCP or UDP (normally you'll be using TCP), select which interface (either Any or Internet; normally it will be Any), and finally enter the target, which can be an IP address (like 10.0.0.1), or a full URL (like http://www.analogx.com:80/).

It is not necessary to configure the security (access control) functions of PortMapper in order to use the port mapping functionality; it's default setting is to allow all traffic. All of the access control is based off of the incoming IP address, that means that if you're running a server, and only want people from a specific IP range to access it, you could do it like this:

    Allow 24.*.*.*

This will let anyone who's IP address begins with 24 to access your site; the '*' star tells it than any value here is Ok. Now, you could also have it deny a specific person's IP within that range like this:

    Deny 24.0.0.0

Now if a user at 24.0.0.0 connects, he'll be denied, but if anyone else from 24.*.*.* connects, they'll be allowed through. You can also have it deny everyone access, by setting it to 'Deny *.*.*.*', and then explicitly telling it which IP addresses (or ranges) are acceptable. You can think of the security feature as a kind of 'best fit' solution; it uses the setting that most closely matches the user.

You can also use this to limit control to a server you run on the same machine; to do this, you need to also configure the port mapping portion of the server to redirect any incoming traffic. Say you're running a webserver on port 80; you would configure the port mapper to map port 80, TCP, from the Internet interface, to localhost (or 127.0.0.1). Then, whenever a machine connects to port 80 from the Internet, it will be filtered through the IP access control - if it's set to deny access, then it won't be able to connect.

If you have a problem getting PortMapper to work with a specific protocol - DO NOT CONTACT ME! I more than likely will not know what needs to be done in order to get things working... The makers of the software you're trying to route are who you need to talk to in order to get things working. If, however, after contacting them and getting the information, you still can't get it going, feel free to contact me; but keep in mind that I probably won't have any of the programs installed on my machine, so will only be able to help you in the most trivial of problems.