When you try to connect, from another device (for example a firewall), to a RADIUS Server installed on a Server 2019, you will experience a connection issue.
So first you will check the local Windows Firewall, if switching it off, everything is fine.
What will be the next step? You are right, switching it back on and checking the rules.
Then you will see, that the corresponding rules where created during the RADIUS installation, so why the heck it does not work?
There is a good article about this “feature”, *sarcasmoff*, at the TopQore Blog:
There you can read in more detail about the bug.
For the lazy ones, the solution is to run the following PowerShell command to set the RADIUS-rules to service “any”:
Get-NetFirewallRule -DisplayGroup “Network Policy Server” | Where DisplayName -like “*RADIUS*” | Set-NetFirewallRule -Service Any
That’s all, after running the above command, you should be able to connect to the RADIUS.
If you want to revert the change, you can run the following command:
Get-NetFirewallRule -DisplayGroup “Network Policy Server” | Where DisplayName -like “*RADIUS*” | Set-NetFirewallRule -Service ias