Testing Port Connectivity

netcat on Linux and MacOS, and Test-NetConnection on Windows.

The netcat tool can be run through the command nc, and has two mandatory arguments, a host and a port.

Running “nc google.com 80” would try to establish a connection on port 80 to google.com

if the connection fails, the command will exit.
If it succeeds, you’ll see a blinking cursor waiting for more input.

If you’re really only curious about the status of a port, you can issue the command with the -Z flag, which stands for zero input output mode. The -V flag, which stands for verbose is also useful in this scenario.

On Windows, TestNetConnection is a command with some of the similar functionality.