Install Network Policy and Access services otherwise called as RADIUS Server. Install the specific role in the new server.
now login to the existing server. Export the existing configuration configuration.
netsh nps export filename="c:\users\usernname\Desktop\NPS.xml" exportPSK=YES
Now login to the new server and import the NPS.xml
if you see any un supported rules . You have to remove them from the old system. Export again and import back to the new server.If you need those un supported rules you need to manually recreate them.
in my case i got three unsupported legacy rules which was created to use a legacy system and it wasn’t exist anymore. so i just deleted those rules and exported and imported back again.
netsh nps import filename="c:\users\usernname\Desktop\NPS.xml"
Now open NPS , Network Policy Server and Click on Register Server in Active Directory.
Now New Network Policy Server is up and running with the same configuration.