When you first start Origin, you will see a License Information dialog box asking you to enter the Host Name or IP address of the FLEXnet server. The Port Number text box should be left blank, except for when there is a firewall between the FLEXnet server and the Origin computers .
After entering the FLEXnet server details and clicking Update, you should see a "success" message. When successful, Origin creates a USE_SERVER.lic file which it then reads at future Origin start-ups. If you need to find the save location for this license file, select Tools:Options and select the System Path tab.
This file will contain:
Where ServerName is the Host Name or IP Address you entered in the License Information dialog box.
And if you also entered the port number due to a firewall, then the USE_SERVER.lic file will contain:
Where ServerName is the Host Name or IP Address, and 61616 is the port number in the SERVER line of the FLEXnet server license file and the port number that you entered in the License Information dialog box.