Also, is it possible to have the AP authenticate against multiple Radius servers? I have multiple domains, and would like my users to authenticate to any of them.
Answer: you can configure APs to point to multiple APs. The APs always go for the first radius server on the list. If you configure radius-server deadtime, the AP will not use the radius server on the top if the radius server does not answer for 3 times. Then, the AP will use the second radius server on the list.