XADM: Site Tear-Down Causes Public Folders to be Re-homed

• Microsoft Exchange Server, version 4.0

SYMPTOMS

The process of deleting a directory replication connector between two Microsoft Exchange Sites (hereafter referred to as Site tear-down) and then re-establishing the directory replication connector might cause undesired affects with regards to public folders such as re-homing and loss of permissions.

CAUSE

Directory replication connectors to other Microsoft Exchange Sites are permanent relationships and were not designed to be torn down and re-established on a frequent basis.

When you delete a directory replication connector, you will see a series of dialog boxes, one stating that the DS/IS Consistency Adjuster should be run to clear up public folder inconsistencies. This dialog box makes the assumption that these Sites will not be re-connected in the future. Once the DS/IS Consistency Checker has been run on each of the affected Sites (each Site involved in the Site tear-down), all public folders that exist in the hierarchy are now homed to each of these individual Sites. This is done to provide transparency to the users of these public folders after the Site replication has been torn down. In other words, if a user in Site1 had access to a public folder that existed in Site2, DS/IS ensures that this same user will still have access to the public folder and its contents after the Site has been torn down. The DS/IS Consistency Checker also ensures that the Access Control Lists (ACLs) are purged of any invalid entries. This process cleanses the folders permissions list of users that existed in the Site that was just disconnected. All of the above is by product design.

The problem arises when these two Sites are re-connected, in other words, you create a directory replication connector between the two Sites that were previously disconnected. Since DS/IS re-homed the public folders to each of the individual Sites after Site tear-down, when the Sites are reconnected and the public folder hierarchy is replicated, a conflict arises because a folder exists in each Site that has the same folder id (FID) yet claims to be homed in two different places. This conflict is resolved by homing the public folder to the Site that has the latest modification to a public folder property. This process could have the following undesired affects:

1. A public folder which was originally created in Site1 when these Sites were connected via directory replication, could be now homed in Site2 after a Site tear-down, DS/IS, and the re-connection of the Sites has taken place.

   rights to the public folder if it was re-homed to a different Site after
   a Site tear-down, DS/IS, and re-connection of the Sites has occurred.

   might no longer have rights after a Site tear-down, DS/IS, and re-
   connection of the Sites has occurred.

WORKAROUND

Do not run the DS/IS consistency adjuster if the directory replication connector has been torn down temporarily and the Sites will be reconnected in the future.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 4.0. This problem was corrected in the latest Microsoft Exchange Service Pack. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K

MORE INFORMATION

It is important to note that the hotfix does not prevent the re-homing from taking place. The hotfix does provide a series of new dialog boxes that pop-up when you perform a Site tear-down. These dialog boxes clearly define the cases in which the DS/IS consistency adjuster should be used as well as describe the implications that running DS/IS could have to public folders if the Sites were to be reconnected. The hotfix also presents a warning dialog box when the DS/IS consistency adjuster is run and provides a Help button on the dialog that brings up a detailed description of the implications to public folders.