TCPView - TCPView is a Windows program that will show you detailed listings of all TCP and UDP endpoints on...
PortsMonitor - PortsMonitor is a system utility for monitoring system TCP/IP network connections by application...
CurrPorts - CurrPorts displays the list of all currently opened TCP/IP and UDP ports on your local computer.
Proc Net Monitor - SecurityXploded is an Infosec Research Organization offering 200+ FREE Security/Password Recovery Tools, latest Research Articles and FREE Training on Reversing/Malware Analysis
Advanced Port Scanner - Advanced Port Scanner is a fast and free software for port scanning.
Port Checker - Check open ports online