I have been playing around with NPS for a while but today was the first time I had ever set up an Network Policy Service Server on a Member Server in a domain. I then wanted to use it as the Primary Server for Authentication for one of our RADIUS clients but couldn’t figure out why I wasn’t getting Authenticated, I had set it up exactly the same as my other NPS Servers. Checking the Event Viewer I noticed that I was receiving the Event ID 4402 reporting that “There is no domain controller available for domain %1”. A lot of posts out on the Internet were leading me in the direction of DNS issues or Firewall issues but none of these were the issue. I then found this post by Geoff @ UVM and it became very clear what I had forgot to do! I forgot to Register the NPS Server in Active Directory. As soon as I had done that, everything started working as expected!

To Register the NPS Server in Active Directory:

1. Open the NPS management console
2. Right-click on NPS (Local)
3. Click on Register server in Active Directory

I won’t forget that one again!

Until next time!