Although telnet is not used regularly since insecure, it’s a handy tool for testing ports.
For example, to check if a port 80 is open, you run this command.
$ telnet servername 80
Git Bash does not come with telnet, but you can use the Windows version by using winpty.
$ winpty telnet servername 457 Connecting To servername...Could not open connection to the host, on port 457: Connect failed
If port is open, you get an empty reply, just like in Windows.