I have searched the forums and not found any similar topic.
We have NPS/RADIUS running on our single DC, on Windows Server 2008 R2 Enterprise, and have had some trouble with RADIUS clients (our wireless access points and some network devices) disappearing from the list. The first time it happened, all RADIUS clients were gone, I had to add them back manually. The second time, I think just one access point disappeared from the client list. Just this week, we again had 1 client disappear. I've looked through the event logs and can't find anything relevant, other than NPS event 13: "A RADIUS message was received from the invalid RADIUS client IP address x.x.x.x" from the client that is no longer in the list. I've backed up our NPS configuration to make restoring it easier, but it's troubling that this is even happening in the first place.
Any ideas?