Removing and adding users in active directory with the same name breaks permissions in Sharepoint 2010?

Question

My company has a procedure to remove and then re-add users with the same name during department transfers (this isn't best practice I guess?).

Presently, the user has problems accessing files in the document library which has been granted to her account by the owner of the document library.

We have configured incremental sync for the user profile service application during the initial farm setup.

Could the above be related to the old IDs (in Sharepoint) not getting updated in the user profile sync?

Answer 1

You have already found the answer because deleting and re-creating an user id in AD does not mean that the SharePoint user profile would understand that. Lets take an example: Step 1: Create an user ABC\MNOP(domain\username) you created in your AD. Step 2: Run the UPS synchronization and once the user is available in SharePoint lets the actual user id would be something like 123;#MNOP. Step 3: Now delete the user and recreate the user with same name and then run the UPS synchronization. Step 4: If could find the user now then user name would be 124;#MNOP* (* Subject to no other users are created within the above process)

So it can be inferred the UPS keeps the user information in it own way but to validate and read the user information it is dependent on AD.