Nmap - Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool. Download open source software for Linux, Windows, UNIX, FreeBSD, etc.
Angry IP Scanner - Open-source and cross-platform network scanner designed to be fast and simple to use
TcpView For Linux - TcpView For Linux. Touch screen friendly design graphical network connections viewer for Linux.
Advanced IP Scanner - Advanced IP Scanner shows all network devices, gives you access to shared folders, and can even remotely switch computers off. Download it Free.
TCPView - TCPView is a Windows program that will show you detailed listings of all TCP and UDP endpoints on...
Advanced Port Scanner - Advanced Port Scanner is a fast and free software for port scanning.