Quest Migration Manager for Active Directory – password error when synchronizing user objects – part 2

In part 1 of this post we explained why QMM Directory Sync Agent (DSA) might run into problems when sychronizing user passwords that have been resetted by using administrative credentials to a value which is present in the password history. In this post we will show how we can identify affected user accounts and how we can work around the issue.
As we have learned in the first part, there are 3 good methods to identify the password synchronization errors:

  • QMM AD GUI – failed objects link in the Status page of the Active Directory synchronization
  • QMM Error Reporter Utility – Quest Utility you can download from support site
  • DSA Log File Parsing – you can parse the log files with any good Parser/Scripting engine

Methods of resolving the password synchronization Problem:

1. User changes password
The simplest approach to solve the problem is the user himself – maybe after contacting the user. When the user changes the password of his Acive Directory account the default way (e.g. via CTR+ALT+DEL). Changing the password this way will ensure that the password policy of the domain is enforced (instead of bypassed via admin reset). Assumed that password policies between source and target domain are aligned, Quest Active Directory Synchronization Agent (DSA) will successfully set the new password on the target user account.

2. User is forced to change password
Another method similiar to 1. is to force the user to change the password by setting the “User must change password at next logon” flag. This can be achieved by using ADUC for single users.


However, when it comes to mass operations, you can achieve the same goal by setting the attribute “pwdLastSet” to “0” programmatically by using Powershell, VB etc.
Approach 1. and 2. have in common that you have to make sure that users do not call the help line and ask for an admin reset to their “usual” password again.

3. Temporary Fine Grained Password Policy controlled by DSA Parser script
Our customers often complain that they do not like to inform users to change their passwords with messages like “your actual password is not compliant with corporate policies – please change”. Educated users will ask: “How come that you know my password. We have been told, admins do not know users’ passwords …
Well, to workaround this situation, a new approach is possible if your target Active Directory domain is Windows 2008 or higher.
The plan:

  • Increase DSA log file size to make sure you have a full DSA cycle in the log (optional). A full cycle will always work once through the failed objects queue and list the password sync Errors.
  • Create a group in target domain that will contain user objects with password sync error.
  • Create a Fine Grained Password Policy (FGPP) in target domain that contains the same password settings as the default domain policy with the exception of password history which is set to Zero
  • Assign the FGPP to the domain group
  • Create a script that parses the DSA log and fills the group. Empty the group before filling to remove already processed accounts

As you can see, the idea is to allow DSA temporarily and only once for the users with password sync problems to bypass the password history setting. This way the password transfer is possible and a further user migration will not end up in a logon error for these users.

From a security standpoint one can argue that bypassing the password history setting is not advisable. We share this opinion, but we have to recognize that the bypassing already started in the source domain. We neither improve the situation during migration, nor do we make it more worse. But we will prevent user logon errors to target domain later.

A scripting example (example, not more 😉 ) can be found here:

Powershell Script INPUT PWDUSER

Quest Migration Manager for Active Directory – password error when synchronizing user objects – part 1

One of the most useful features of QMM Active Directory synchronization is the ability to synchronize the password of user objects between Active Directory Domains. While Microsoft’s Forefront Identity Manager (FIM) first needs to capture the user password on the Domain Controller when the user actual changes the password, QMM can transport the password hash directly at any time. While FIM needs to install an agent on every Domain Controller to capture the password changes, QMM places an agent “on the fly” on only one dedicated Domain Controller. This can make a big difference in large Active Directory infrastructures.
However, running a long term “ongoing continous” Active Directory synchronization often shows one or many errors like this (snippet from Migration Manager GUI) and fails to update the password to the actual value:


The error is a  bit misleading here. QMM is purely transporting the password hash and therefore cannot measure the length of the user password nor can QMM prove the complexity. That means, we have to deal with a password history problem. Assuming we have the same password policies in source domain and target domain and an ongoing password synchronization, this error may never come up, because the password history policy of the source domain would prevent the user to change the password to a value that is still in the password history store.
But there is a second method of changing passwords: The admin reset of passwords. When an admimistrator changes (resets) the password on behalf of a user, he can set the password to a value that is in the password history store. An administrative reset can bypass the password policy. Our investigations showed that several users bypassed the password history policy by calling the help line …
After the administrative reset of the password in source domain, QMM directory synchronization agent (DSA) recognizes a change of the password of the user object and tries to replicate the password hash to the target domain user object. But the DSA has to go “through” the password policy check like a standard user password change which finally results in the password error message above.

You also can find specific error codes in the DSA log file:
05/07/13 08:32:45 (GMT+01:00)     Common AcAdSwitches Error 0xe100004f. Cannot synchronize passwords, source user: “<user name>”, target user: “<user name>” Error 0x8007052d. Unable to update the password. The value provided for the new password does not meet the length, complexity, or history requirements of the domain.

In part 2 of this post, we will show ways to work around the password sync error.

QMM AD – Incorrect Directory Synchronization Agent Matching, Caching and Repairing

QMM AD stores matching data in ADLDS and in Cache DB

From our experience, the Directory Service Agent component (DSA) from Quest Migration Manager for Active Directory is a reliant and powerful way to synchronize Active Directory objects and attribute data from one domain to another (and vice versa). It also has the ability to synchronize user passwords by installing a single agent on one domain controller. More than this, DSA is also responsible for mailbox creation in the Quest setup and synchronizes mailbox and Active Directory permissons.

The speed of delta synchronization (synchronizing changes of object attributes) is a combination of matching and caching. Quest DSA uses an AD LDS database to create matching objects that describe the synchronization relationship between an object in source domain and its peer in the target domain.

However, the ADLDS matching objects are most important when starting the synchronization and performing a Full Resync. In the ongoing synchronization, DSA takes the matching information from its cache which is a JET database located in “…\DSA\CONFIG\Cache” directory. The cache database file can grow up to a size which exceeds the size of the AD LDS by far. If disk space matters on your DSA machine, have an eye on the cache file size first.

DSA cache files

Solving incorrect matching

By default, Quest Active Directory sync knows 3 criteria for object matching (the way, how DSA identifies, whether it has to merge an existing account in target or create a new one) – mail address, sid-sidHistory, samAccountName. Both decisions (merge or create) have consequences since DSA will create or modify the matching object and bind objects together, that should form a unity (or not).


However, we do not live in a perfect world and situations occur where the matching went wrong.

Real word scenario:

  1. Group A is created in source domain, mail-enabled and filled with 10 members. It is part of DSA migration scope.
  2. DSA picks up the group and looks up the matching criteria. All 3 criteria are activated and mail has highest precedence. DSA does not find a peer and creates a new group A in target domain with e-mail and the link resolver fills the group membership with the target user objects. DSA also creates a matching object and updates the cache file. So good so far.
  3. Now somebody decides to create a new group B in source domain and shifts the mail address from group A to group B while the mail address on group A is renamed in the same step.
  4. DSA will recognize that group B is existing and looks up for matching criteria. It will find a match for the mail address in group A of the target domain and will set up a matching of group source B to target A. It also will replicate the membership from source B to target A.
  5. We have now a lot of uncomfortable issues. Membership in the DLs looks different for users in source and users in target domain. Group A in target has 2 entries in sidHistory, one for source group A and one for source group B. The matching attribute in group A from target domain is now filled with the object GUID from group B in source domain and the proxyAddresses including X.500 are mixed as well. Other attributes depend on your skip list settings
  6.  And we still have group A in source. Since the matching criteria of sid-sidHistory is still valid, you can end up with a flip/flop, so that DSA runs over the two accounts and whenever there is a new attribute change on one of the source groups, it can either be group A or group B which is merged to group A in target.

OK, we should try to clean up the confusion.

  1. We better remove mail address matching in our setup since it has problems with the domestic way of changing groups in this customer environment. We clean up all wrong values of group A in target. We run a full resync (which is restricted to once per quarter)
  2. Same thing again, because the matching attribute was filled with the wrong value and the matching sid-sidHistory was still in place.
  3. We clean up again and delete the matching attribute. We modify group B in source to trigger DSA and expect that a new group B in target is created.
  4. Do we succeed? No. Of course not. There is a wrong matching object for group B (and group A) in ADLDS. OK. We clean up again and we delete the matching objects in ADLDS.
  5. No way. The same thing happens again. No group B in target, but a matching of group A and group B to group A in target.
  6. This time we stop DSA, clean up group A in target domain including wrong entries in proxyAddresses, sidHistory and delete the matching attributes. We delete the cache file and start with Full Resync – and we succeed

It’s all about cache. All the cleanup and repair actions can fail as long as the cache file still contains the wrong linking. Since a selective cleaning of the wrong object matching of the cache is not possible (anyone to try?), we always will need a full resync (of thousand objects) to repair a single object pair with wrong matching.

An alternative would have been to delete all 3 groups and create fresh objects. I would call it the “brute force method”. Not acceptable in many cases though.