Article ID: 938703 - View products that this article applies to.
This article discusses how to troubleshoot LDAP over SSL (LDAPS) connection problems.
To troubleshoot LDAPS connection problems, follow these steps.
Step 1: Verify the Server Authentication certificateMake sure that the Server Authentication certificate that you use meets the following requirements:
Step 2: Verify the Client Authentication certificateIn some cases, LDAPS uses a Client Authentication certificate if it is available on the client computer. If such a certificate is available, make sure that the certificate meets the following requirements:
Step 3: Check for multiple SSL certificatesDetermine whether multiple SSL certificates meet the requirements that are described in step 1. Schannel (the Microsoft SSL provider) selects the first valid certificate that Schannel finds in the Local Computer store. If multiple valid certificates are available in the Local Computer store, Schannel may not select the correct certificate. A conflict with a certification authority (CA) certificate may occur if the CA is installed on a domain controller that you are trying to access through LDAPS.
Step 4: Verify the LDAPS connection on the serverUse the Ldp.exe tool on the domain controller to try to connect to the server by using port 636. If you cannot connect to the server by using port 636, see the errors that Ldp.exe generates. Also, view the Event Viewer logs to find errors. For more information about how to use Ldp.exe to connect to port 636, click the following article number to view the article in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/321051/ )How to enable LDAP over SSL with a third-party certification authority
Step 5: Enable Schannel loggingEnable Schannel event logging on the server and on the client computer. For more information about how to enable Schannel event logging, click the following article number to view the article in the Microsoft Knowledge Base:
260729Note If you have to perform SSL debugging on a computer that is running Microsoft Windows NT 4.0, you must use a Schannel.dll file for the installed Windows NT 4.0 service pack and then connect a debugger to the computer. Schannel logging only sends output to a debugger in Windows NT 4.0.
(https://support.microsoft.com/kb/260729/ )How to enable Schannel event logging in IIS
Article ID: 938703 - Last Review: June 21, 2014 - Revision: 3.0