RADIUS Usage
Once you have configured your RADIUS client, it is recommended that you verify RADIUS connectivity using a testing utility such as NTRadPing before reconfiguring your VPN appliance. After verifying RADIUS connectivity, you may configure your appliance to use the ESA RADIUS server as an external authenticator for your VPN users.
Since both the optimal authentication method and usage are dependent on your appliance make and model, see the relevant ESET Secure Authentication VPN integration guide, available on the ESET Knowledgebase.