I have been happily using the LDAP module to allow users to authenticate to my site using their Active Directory credentials. This has been working great. New user accounts, that successfully authenticate via LDAP, are automatically created the first time they log on to the system.
I now face the challenge that we will be migrating to a new domain and all of our Active Directory credentials will be changed, primarily username and quite possibly GUID.
I'm trying to figure out how to connect my existing drupal user accounts to the new Active Directory system. I am currently using the AuthName Attribute: sAMAccountName. I thought perhaps the email address would be a good authentication point since that will not be changing in the new system. However, when changing the AuthName attribute to 'mail' on my test system and giving it a try, I run into problems. The system is trying to create a new user, but thinks that a user with the specified email address already exists (which it does).
So, how do I keep my current Drupal user accounts in tact, but authenticate to a new LDAP system with new credentials?
Please let me know if I can provide any additional information to explain the scenario further.