RD Session host is unable to receive license from RDS CAL server

Question

We have activated the user based RDSCAL license in one of the windows 2k19 server and license is not issued to the users when user tries to connect to the session host servers.

When we try to validate from the RD License Diagnoses in the RDSH server, we can see 20 licenses are available for the clients. But when we try to connect more than 2 users to the RDSH server - it is prompting to disconnect any one of the 2 connected users (which we connected for testing).

Answer 1

Hi Bblythe Xiao,

I would like to share the resolution for the issue that I posted in this forum.

We have CyberArk configured as PAM for any server logins within the environment. We have 2 PSM (Privileged Session Manager) servers, setup with a Remote Desktop Connection broker for the Windows based user login to servers. We identified that the RDS connection was successful from the first PSM server, but failing when the user sessions are hitting the second PSM server. This was confirmed with the TCP connection test from the second PSM server and it was failing for TCP port 3389 to our destination RDSH servers. There were no configuration issues identified in the non-working PSM server as both were built from the same Image with identical configuration. The network log analysis at different integration points suggested there were no restrictions in terms of traffic movement. During the tests, a communication was initiated from the non-working PSM server, and it was noticed in logs that the TCP acknowledgement packets were not received by the PSM server from the RDSH servers. Upon further checking, it was noticed that an inbound rule was missing in the internal firewall device for the new subnets hosting the RDSH servers.

Once the firewall rule was added, the connection started working fine through the second PSM server and CALs were issued properly as expected.

I would like to thank you for your assistance throughout our troubleshooting, and request to mark this post as resolved.

Regards,

Arindam Basu.

Answer 2

Hello ARINDAM BASU_DXC,

Thank you for posting in the Microsoft Community Forums.

It's possible that your Remote Desktop Licensing Server is not configured correctly. You can troubleshoot by following the steps below.

Group Policy settings:

(1) Open the Group Policy Editor (gpedit.msc)

(2) Go to Computer Configuration - > Administrative Templates - > Windows Components - > Remote Desktop Services - Remote Desktop Session Host > - > Licenses

(3) Check the following settings. - Use a specified Remote Desktop license server: Enabled Specify the FQDN or IP of the license server - Set Remote Desktop Licensing Mode: Enabled Specify the type of license (per-user or per-device)

(Note: If any changes are made to the group policy, you will need to run the "gpupdate /force" command as an administrator in the command prompt.)

Registry settings:

(1) Navigate to Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services.

(2) Check the value of LicensingMode to make sure it is set on a per-user basis (per-user CAL key value of 4, per-device CAL key value of 2)

(3) Navigate to Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\Licensing Core.

(4) Check the value of LicensingMode to make sure it is set on a per-user basis (per-user CAL with a key value of 4, per device CAL with a key value of 2)

(5) Navigate to Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\TermService\Parameters\LicenseServers.

(6) Add SpecifiedLicenseServers and specify the FQDN or IP of the license server

(7) Navigate to Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsNT\Terminal Services.

(8) Add LicenseServer and specify the FQDN or IP of the license server.

I hope the above information is helpful to you.

If you have any doubts, please feel free to let me know.

Best regards

Bblythe Xiao

Answer 3

Hi Bblythe Xiao,

Thanks for your response.

The steps provided by you are in place. The GPO settings are proper, and it is applied to the RDSH servers. The registry settings are showing correctly as per your feedback. We are using per-user CAL.

However, we are still facing the same issue.

Answer 4

Hello ARINDAM BASU_DXC,

May I ask what the operating system versions are for the session host and licensing server, as well as the version of RDS CAL in your RDS environment?

And does it comply with the CAL usage rules that the licensing server version is greater than or equal to the CAL version, and the CAL version is greater than or equal to the session host version?

Best regards

Bblythe Xiao

Answer 5

Hi Bblythe Xiao,

We have 2 RDSH and one CAL server, and all three are running on Windows 2019.

Regards,

Arindam Basu.