FLEX LM uses random ports every time it's started, but if you're keen on using another port other than 23, then look for the .LIC file in the installation directory and search for: VENDOR safe PORT=yyyy where yyyy is the port name. Edit the file and restart all the services and the new port will be used.
The server uses the ports between 27000 and 27009, while the VENDOR port is between 1700 and 8000.
