It is a freeware Windows 95/98/NT/2000/XP utility that lets you to calculate every aspect of your subnet configuration in a few mouse clicks! It was designed for any network engineer who needs a fast way to determine subnets.
Advanced Port Scanner is a small, fast, easy-to-use and robust LAN scanner for the Win32 platform. It is multithreaded, so on fast machines you can scan many computers at once.