While installing Symantec Endpoint Protection Manager, you see the following message: "Port 1812 is already in use. Stop your Radius server if you have the Enforcer installed."
The Symantec Endpoint Protection Manager uses Radius communication and requires port 1812 to be available for the Enforcer (see References below). If a Radius Server is already installed it may be using the same port. Other installed software may also be using this port.
To solve the problem, either change the port the Endpoint Protection Manager uses, change the port that the existing Radius server (or other third-party software) uses, or install the Symantec Endpoint Protection Manager on a different computer on which port 1812 is not in use.
To change the port the Endpoint Protection Manager uses
Navigate to C:\Program Files\Symantec\Symantec Endpoint Protection Manager\tomcat\etc\.
Open the conf.properties file.
Add a line at the bottom that reads:
where xxxx is the desired port number.
Press Enter in order to leave a blank line at the end of the conf.properties file.
Save and close the conf.properties file
Restart the IIS Admin Service
Click Start > Run
Type services.msc and click OK
Right-click on IIS Admin Service and click Restart
Click Start > All Programs > Symantec Endpoint Protection Manager > Management Server Configuration Wizard and complete the wizard.