XADM: Changing the Port Used by the Exchange Server 5.5 Directory for LDAP over SSL

When Exchange Server is installed on a Windows 2000 domain controller, the Exchange Server directory service has no way to use a non-default port (636) for Lightweight Directory Access Protocol (LDAP) Secure Sockets Layer (SSL) communication. In the event log the following error may be found:

This issue occurs when Exchange Server is running on a system that already has a Directory service using this port and when Exchange Server is installed on a Windows 2000 domain controller.

If you set the Incoming-Msg-Size-Limit attribute to, for example 637, using the Exchange Server Administrator program in raw mode, you can effectively change the port used by the Exchange Server LDAP SSL service for listening. To do so:

WARNING: If you use the raw mode of the Exchange Server Administrator program (admin /r) incorrectly, serious problems may occur that may require you to reinstall Microsoft Windows NT Server, Microsoft Exchange Server, or both. Microsoft cannot guarantee that problems that result from using raw mode incorrectly can be solved. Use raw mode at your own risk.

Install the latest service pack for Exchange 5.5

1. Start the Microsoft Exchange Server Administrator program in raw mode by typing the following at a command prompt:
   c:\exchsrvr\bin\admin /r
2. Select the Protocols container of the Site or Server which depends on the scope of this setting.
3. Select the LDAP component.
4. On the File menu, click Raw Properties.
5. In the List Attributes of the Type drop-down box, select All.
6. In the Object Attributes list, scroll down to, and select the Incoming-Msg-Size-Limit attribute.
7. In the Edit Value text box, type the port you want to use.
8. Click Set and make sure the Edit Value and Attribute Value are the same.
9. Click OK to close the dialog box.
10. Stop and restart the Exchange Server Directory service.

Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5. This problem was first corrected in Exchange Server 5.5 Service Pack 3.

To resolve this issue, obtain the latest service pack for Exchange Server version 5.5.

For additional information, please see the following article in the Microsoft Knowledge Base: