Migrating NPS Settings from Old Domain Controller to New Domain Controller

If you're using RADIUS on your Windows network, and you need to do Domain Controller upgrades, rebuilding RADIUS can be a pain if there are a lot of entries.  Using this process, you can easily back it up and then restore it on the new server.

NOTE:  This process assumes you are using the same name and IP address on the new OS for your new DC.

1.  Backup NPS on the old server.  Run this command:

netsh nps export filename="C:\NPS-Export.xml" exportPSK=YES

2.  For good measure, backup DHCP as well.

netsh dhcp server export C:\dhcp.txt all

3.  Copy these two files to a place where you can access them on your new DC.

4.  Once your new OS is promoted to a Domain Controller with the same name and IP address as the old DC, you can begin the import process.

5.  Install NPS on the new DC.

Install-WindowsFeature NPAS -IncludeManagementTools

6.  Import your NPS configuration file

netsh nps import filename="C:\NPS-Export.xml"

7.  Register NPS in AD

netsh ras add registeredserver

8.  Restart the NPS service

net stop ias

net start ias

PRO TIP:  Just in case, it's a good idea to grab a backup of the NPS registry key.  I personally haven't had to use it but it can't hurt to have it.

reg export HKLM\SYSTEM\CurrentControlSet\Services\IAS C:\NPS-Registry.reg

That's really all there is to it.  Good luck!