Whenever you run a server on your machine, it uses what are called 'ports', which allow other machines to connect to them. Of course, sometimes you're just running them for your own internal use, but there's no easy way to stop someone from accessing the server. AnalogX PortBlocker allows you to basically block the Internet port of most servers, making them unreachable to other computers on the Internet. This program is NOT a Firewall, but it will allow you to run a server that is only available on the local network, and will log any access attempts made by other machines that are attempting to use the blocked interface. By default, PortBlocker is configured to block the most common types of servers that might be on a system (FTP, HTTP, etc), so will not require any modification for most users. If you are running a special server of some sort, then you can easily add it's ports (either TCP or UDP) to it's list, and have them blocked and/or logged.