Configure one or more external RADIUS servers in the Security > AAA > RADIUS section.
Enter the servers IP address and the shared secret key that the wireless controller uses to communicate with the RADIUS server and ensure the server is set to Enabled.
To use the RADIUS server with wireless network clients make sure the Enable box to ticked next to Network User.
Navigate to WLANs and select the WLAN to edit. Configure the WLAN security under WPA2 Enterprise.
On the Security -> Layer 2 tab select WPA+WPA2 and ensure WPA2 Policy is ticked and WPA is not.
Check the box next to WPA2 Encryption that indicates AES to use the best encryption.
Select 802.1x under Authentication Key Management to enable the enterprise mode. Make sure PSK is not checked so Personal mode is left disabled.