If you use WPA-Enterprise or WPA2-Enterprise on your network, clients must be authenticated via a RADIUS server, and even if you don't use those wireless standards, RADIUS provides an effective way of providing centralized authentication. Troubleshooting RADIUS issues involves both ensuring that the access point/router can connect to the RADIUS server, and that the client can log in to the RADIUS server.
Verify that the RADIUS server has a secret configured and that it is set up to accept connections from the access point/router, which should be configured to connect to RADIUS with a matching secret. Also, verify connectivity between the access point/router and the RADIUS server. There are different ways of doing this but using ...
