Windows
The ArcGIS License Manager starts automatically when you reboot your computer after the installation is complete.
Also refer to Starting and stopping the License Manager.
Linux
Once you have installed and started the license manager on your network, configure the license manager to start automatically when the system boots, even though it is not required.
Platform-specific instructions for this operation on Linux are found in the license.boot file located in your License Manager installation location.
To start the ArcGIS license manager automatically at boot time, you must use the license.boot file, and you will need to modify this file to reflect your system information.
Also refer to Starting and stopping the License Manager.