netstat

Netstat is a command line utility to display all the network connections on a system. It displays all the tcp, udp and unix socket connections. Apart from connected sockets it also displays listening sockets that are waiting for incoming connections.

Visit the following resources to learn more:

• netstat command in Linux with Examples
• Netstat Tutorial
• Netstat Commands - Network Administration Tutorial
• Linux Command Line Tutorial For Beginners - netstat command