Hello,
In the scenario where the Remote Desktop Licensing Server (RDLS) is set up on a separate server from the Remote Desktop Session Host (RDSH), it's necessary to configure the server bearing the RDSH role to direct to the RDLS server's address via Group Policy. Additionally, the license mode must be set up accordingly. However, we're uncertain about the specific distribution of these two roles across your two servers.
Please note, if your RDS deployment utilizes workgroup servers, Per Device CALs are mandatory, as Per User CALs are not supported in such a setup.
Another crucial aspect is ensuring compatibility between the versions of your RDS CALs, RD Session Hosts, and RD License Servers. This also entails verifying there is proper network communication between the RDSH server and the RDLS server.
It's important to remember that there's a 120-day licensing grace period, wherein a license server isn't mandatory. However, following this period, clients attempting to log onto an RD Session Host server must possess a valid RDS CAL provided by the license server.
Lastly, don't forget to examine the Event Viewer for any detailed logs pertaining to licensing issues for further insights: https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/ff404145%28v=ws.10%29#remote-desktop-licensing
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