if u r interesting in hacking then u should know about port scanner.it is utility to test open port and to test vulnerability of your target system.there is a lot of tool available on the net but the most famous tools is SATAN .
it developed to test network weakness.it is available for unix plateform and to use this scanner u should install unix.
i think it is very hard to get download url of satan because it is restricted for public use.
in most country port scanning is restricted like america etc so plz be carefull...
if u want to downlaod click on this
http://linux.softpedia.com/get/System/Networking/SATAN-23306.shtml
and one mirror site is http://www.porcupine.org/satan/mirrors.html
the speed of scanner depend upon the thread that are using by scanner.
One other windows based scanner is nmap.It is used in actual in hollywood movie Die hard-4.
it is also a fastest port scanner.
if u want to download nmap click on this http://nmap.org/download.html
THE INFORMATION GIVEN BELOW IS ONLY FOR EDUCATIONAL PURPOSE & I WILL NOT BE RESPONSIBLE FOR HOW U USE THIS INFORMATION
