We will be setting up a tertiary RADIUS server at a remote site. Up until now, changes to the RADIUS database has been done manually, since it was only 2 servers. With a third one coming online I wanted to see if there is some way to sync the changes between RADIUS servers using Windows Server 2008 R2.
SnapOverflow
Why not use an active directory back end? If you do this, you will only have to update the appropriate groups once instead of on all servers? This is very easy to configure in NPS.
I just came across your question. I have been working with nps in windows 2008/2008r23 alot recently. If you haven't found a good solution for this problem I might have one.
Decide on which of your servers is going to be your master. Make your chances on this server. Using powershell you can export the configuration for nps including shared secrets to a config file. It will not include sql database accounting setup. You can save it on a shared location between your servers. Then on the slave server (your servers that you want to apply your changes to) you can run the powershell import. You can script the export and import on your servers.
Export Config from powershell prompt on master server
netsh nps export filename = "C:\config.xml" exportPSK = YES
Import Config from powershell prompt on slave server
netsh nps import filename = "C:\config.xml"
You can script this and also substitute any shared storage you have between the servers. With powershell you can copy the file over to your remote servers with
copy-item C:\Config.xml \server\share\Config.xml
Potentially you could take these pieces and with a little more powershell and have a script that you run whenever you make a change that will push out the change to all of your nps servers.
When I was looking for a solution for this problem, I found this article by Microsoft:
Manage Multiple NPS Servers by Using the NPS MMC Snap-in
If anybody has the same issue, I hope this link will help.