TCP Port Listener Tool for verifying connectivity when testing or configuring network components. Features: Locally create a simple TCP listener on any port Connect to any TCP listener remote or locally Send messages back and forth Establishing a Network and Testing the Connection Just define port and start listen and send commands This program is free of charge Most online port testers fail no matter what if nothing accepts their connection attempt. This port tester program will open the port on the system it is running on and listen for a connection from this site. So when the port tester program says the ports are open you can count that they are :-) The port tester program is for testing connections to the machine the program is running on since it opens the port on that system and listens for a connection.