In this scenario, you find that the servers are re-requesting and re-enrolling the certificates two times daily. This occurs even though the certificate template is valid for one year. Additionally, when the re-enrollment of the certificate occurs, the following event is logged in the System log:
Log Name: System Source: Microsoft-Windows-TerminalServices-RemoteConnectionManager Date: DD/MM/YYYY hh:mm:ss Event ID: 1063 Task Category: None Level: Information Keywords: Classic User: N/A Computer: <Server1> Description: A new template-based certificate to be used by the terminal server for Transport Layer Security (TLS) 1.0\Secure Sockets Layer (SSL) authentication and encryption has been installed. The name for this certificate is <Server1>. The SHA1 hash of the certificate is provided in the event data.
Additionally, if you have these enrolled certificates automatically published to Active Directory, the size of the Active Directory database will increase significantly because of the constant re-enrollment of the certificate. And, the Active Directory replication may pause and report the following Warning event:
Event Type: Warning Event Source: NTDS General Event Category: Replication Event ID: 1079 Date: DD/MM/YYYY Time: hh:mm:ss User: <DOMAIN>\<DC2$>$ Computer: <DC1> Description: Internal event: Active Directory could not allocate enough memory to process replication tasks. Replication might be affected until more memory is available.
Increase the amount of physical memory or virtual memory and restart this domain controller.
The underlying cause of this behavior is related to the RDS component and to a mismatch within the certificate template. Specifically, if the template name and template display name are different, the RDS service does not match the existing certificate to the template, and the RDS service periodically enrolls a new certificate.
To resolve this problem, you must set the certificate template's attribute's template display name and template name to the same value, such as RemoteDesktopComputer. This procedure is suggested in the following Microsoft TechNet article:
Then, you must update the GPO setting Computer Configuration\Policies\Administrative Templates\Windows Components\Terminal Services\Terminal Server\Security\Server Authentication Certificate Template based on the new template name, such as RemoteDesktopComputer. After the server receives the new GPO setting during the processing of the background GPO redraw, the certificates are no longer renewed on a twice-daily basis.
Important: You must set the certificate template’s attributes Template Display Name and Template Name to the same value.