Outdated Active Directory objects generate event ID 1988 in Windows Server 2003

Symptoms

On your Microsoft Windows Server 2003-based domain controller, the following Error event is logged in the Directory Service event log:

Cause

This issue occurs if the source domain controller has outdated objects that have been out of replication for more than one tombstone lifetime. The source domain controller is identified in the event message. These outdated objects are referred to as lingering objects. A domain controller that was offline for longer than the value of the tombstone lifetime setting may contain objects that have been deleted on other domain controllers or global catalog servers. The default tombstone lifetime value is 60 days. Additionally, tombstones for these objects may no longer exist. When you bring the outdated domain controller back online, it cannot be notified of the object deletions.

Resolution

To resolve this issue, you can use the Repadmin tool to remove lingering objects from a directory partition. The repadmin /removelingeringobjects command does the following:
  1. Designates an up-to-date domain controller as the authority. This domain controller acts as the authoritative directory replica.
  2. Compares the Active Directory Directory service database objects on the authoritative server with the objects that are on the source replication partner that contains the lingering objects.
  3. Either removes the lingering objects or logs the potential deletions to the Directory Services event log. The behavior depends on whether you use the /advisory_mode parameter.
To use the repadmin /removelingeringobjects command, follow these steps.

Note To use the repadmin /removelingeringobjects command, both the source domain controller and the destination domain controllers must be running Windows Server 2003.
  1. Install the Repadmin tool. The Repadmin tool is included with the Windows Server 2003 Support Tools that are included with the Windows Server 2003 CD-ROM. To install the support tools, double-click
    Suptools.msi in the
    CD_Drive:\Support\Tools folder.
  2. At the command prompt, type repadmin /removelingeringobjects Destination_domain_controller
    Source_domain_controller_GUID
    Directory_partition /advisory_mode
    , and then press ENTER.

    Note The /advisory_mode parameter is optional. You can use this parameter to make sure that the lingering object that is reported in event ID 1988 exists in the Active Directory database on the server that you suspect has the lingering objects. When you use this parameter, the lingering objects are not removed. Instead, the /advisory_ mode parameter lets you view the results of the command before you take action to remove any objects from the folder. We recommend that you always use the /advisory_ mode parameter before you use Repadmin to delete the lingering objects.
    • Destination_domain_controller is the domain name system (DNS) name or IP address of the domain controller that has lingering objects. In the event ID 1988, this value is the server that is identified in the source domain controller field.

      Note You can use the dc_list parameter if you want to specify multiple destination domain controllers that have lingering objects. Because lingering object removal is not replicated to other domain controllers, you must run the repadmin /removelingeringobjects command against all destination domain controllers and global catalog servers that have lingering objects. For more information about the dc_list parameter, type repadmin /listhelp at the command prompt, and then press ENTER.
    • Source_domain_controller_GUID is the object GUID of the source domain controller that you are using as the authoritative server. To obtain the object GUID of the source domain controller, use one of the following methods.

      Method one

      At a command prompt, type repadmin /showrepl /v
      name of the authoritative server
      , and then press ENTER. The object GUID of the domain controller is listed in the
      DC object GUID field.

      Method two

      Use the Active Directory Sites and Services tool to locate the object GUID of the source domain controller. To do this, follow these steps:
      1. Click Start, point to
        Administrative Tools, and then click Active Directory Sites and Services.
      2. Expand Sites, expand the site where your authoritative domain controller is located, expand
        Servers, and then expand the domain controller.
      3. Right-click NTDS Settings, and then click Properties.
      4. View the value in the DNS Alias box. The GUID that appears in front of
        _msdcs.forest_root_name.com is the object GUID of the domain controller. The Repadmin tool only requires the GUID. Do not include the
        _msdcs.forest_root_domain_name.com component in the Repadmin syntax.
    • Directory_partition is the distinguished name (DN) of the directory partition that contains the lingering objects. This is part of the
      object_distinguished_name in the event message.
  3. Repeat the procedure for the following partitions, as needed:
    • Domain directory partition (dc=domain_DN)
    • Configuration directory partition (cn=Configuration,dc=forest_root_DN)
    • Application directory partition or partitions
      (cn=Application_directory_partition_name,dc=domain_DN)
      (cn=Application_directory_partition_name,dc=forest_root_DN)
    • Schema directory partition (cn=Schema, cn=Configuration,dc=,dc=forest_root_DN)

More Information

Example of the command syntax

The following is an example of the repadmin /removelingeringobjects command syntax for the fictional Example.com domain:
C:\>repadmin /removelingeringobjects domain_controller.example.com A0AE6093-15F5-4DB8-836B-4495E3A15396 dc=example,dc=com /advisory_mode
If the command runs successfully, you receive the following message:
RemoveLingeringObjects successful on
domain_controller_name.domain_name.com


Note To access the Repadmin tool advanced help, you can use the /experthelp parameter.

Events that are associated with lingering object removal

When you remove the lingering objects, the domain controller with the lingering objects records all removal information. This information includes the source domain controller, the objects that are removed, and a total count of all the objects that are removed. During lingering object removal the following events are logged to the Directory Service log:For more information about lingering object removal in Windows Server 2003, see the "Lingering Object Removal" topic on the following Microsoft Web site:

Falsely reported lingering objects

If you check the domain controller by using the Repadmin tool together with the removelingeringobjects syntax in advisory mode, you may find that some objects that have been deleted are reported as lingering in the following directory service event log: This event may be logged when a deleted object is already garbage collected on the source domain controller, but the deleted object is not yet garbage collected on the destination domain controller. In this case, the Repadmin tool detects the objectGuid of the object and reports it as a lingering object. Additionally, the objectGuid of the object is still present on the destination domain controller, but the objectGuid of the object is not present on the source domain controller. Because this object will be removed during the next Garbage Collection cycle, you can safely ignore all NTDS replication 1946 events that contain the object GUID.

When an object is deleted, the isDeleted attribute is set to TRUE. This change of the isDeleted attribute is the last object change that is replicated. Garbage collection refers to the removal of an object from the NTDS database. Garbage collection is a local process on the domain controller. This final change is not replicated. In some cases, an object is reported as lingering when it was created on the destination domain controller, but the object has not yet been replicated to the source domain controller. You can check this by using the Repadmin tool together with the removelingeringobjects syntax after the typical replication delay time span. If the object is not reported as lingering, you may also safely ignore it as a falsely reported lingering object.
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Номер статьи: 870695 — последний просмотр: 5 февр. 2008 г. — редакция: 1

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