Many times, you are not sure if the port is open between the Simio GUI (client) and the Simio Network License Server. The program in the attached zip will allow you to test whether the port is open. Just unzip the CheckPort.exe from the attached zip file. Then run the program and enter the host and port. If you get a Socket Exception, you cannot connect to the server / port. If you get a message saying "Socket connect to...", the port is open.