Testing Open Ports With NetCat or Powershell

Ok so it’s 2021. We all know telnet is a dumpster fire no self respecting system engineer wants on their boxes. So what’s the alternative when troubleshooting whether you can connection a port or not. So lets take a look at alternatives below:

Linux with NetCat

 nc -zv <hostname or ip> <port number>

If your connection was successful you’ll get a message back like this

Connection to example.com port 80 [tcp/*] succeeded!

If your connection was not successful it will hang until it times out, at which point you’ll get a message indicating it failed with operation timed out.

Windows with Powershell

Test-NetConnection <hostname or ip> -Port <port number> -InformationLevel Quiet

This will return simply a true of false. If you want more detailed information you can use Detailed instead of quiet or simply omit the -InformationLevel flag and everything after it.