LiveTcpUdpWatch - View TCP/UDP network activity of every application on Windows
CurrPorts: Monitoring TCP/IP network connections on Windows
TCP Port | OpsRamp Documentation
Port Monitor - Website and server monitoring made simple!
Automatic TCP port monitoring – Zabbix Blog
Network Open TCP/IP And UDP Ports Monitor Tool
PA Server Monitor Documentation - TCP Port Monitor
Zabbix Team on Twitter: "Have you ever wanted to automatically discover and monitor all your listening TCP ports for one machine? In this #ZabbixBlog post, we will teach you another simple way