What the port Probe scan tool does is that it uses nmap to test if you have open ports.

It can only do so for TCP as UDP is connection-less ( you can't test if the packet was received or not on a destination )

You can use iptables to block ports IPTABLES -I INPUT -p -s --dport -j DROP to block requests

The tool does a test to see if your host is up by pinging. Be sure it allowes ping first.

You can get more information about the nmap project on their mainpage at