Netcat: Creating a Listening Port
Creating a Listening Port
Having a server that listens is good, but when testing with a firewall and you don't necessarily have the listening port behind it yet, you can simply use the Netcat command.
This command will act as if it were a server-type service that starts listening:
or
The command varies depending on the version of netcat.
If you want the connection to remain open:
Then all you need to do is test it: