Events 6804 and 2843 are logged and RODCs do not replicate SYSVOL

Symptoms

One or more read-only domain controllers (RODC) do not replicate inbound the system volume (SYSVOL) shared directory. This issue occurs even though multiple inbound Active Directory connections are listed when Active Directory Sites and Services (Dssite.msc) is pointed at an affected RODC. 

When this issue occurs, the following entry is logged in the DFSR event log:

Log Name: DFS Replication
Source: DFSR
Event ID: 6804
Level: Warning
Keywords: Classic
Description:
The DFS Replication service has detected that no connections are configured for replication group Domain System Volume. No data is being replicated for this replication group.
Additionally, the following entry is logged in the Directory Service event log:

Log Name: Directory Service
Source: Microsoft-Windows-ActiveDirectory_DomainService
Event ID: 2843
Task Category: Knowledge Consistency Checker
Level: Error
Description:
The Knowledge Consistency Checker was unable to locate a replication connection for the read-only local directory service. A replication connection with the following option must exist in the forest for correct FRS system behavior.

Additional Data
Option: 64
User Action
Restore the original replication connection for the local directory service instance on a writable directory service instance.
When this issue occurs, new RODCs that are promoted work correctly. Also, demoting and promoting an affected RODC fixes the issue.

Note Outbound replication also does not occur. However, this behavior is by design on an RODC.

Cause

This issue occurs because an administrator has deleted the automatically generated "RODC Connection (FRS)" objects for these affected RODCs. This action may have been done for one of the following reasons:

  • A customer notices that the connections are named "FRS" and, therefore, believes that the connections are no longer required because DFSR is replicating SYSVOL.
  • The administrator created manual connection objects per local processes.
RODCs require a special flag on their connection objects in order for SYSVOL replication to work. If the flag is not present, SYSVOL does not work for FRS or DFSR.

Resolution

To resolve this issue, follow these steps:

  1. Log on to a writeable DC in the affected forest as an enterprise administrator.
  2. Start Dssite.msc.
  3. Navigate to an affected RODC within its site, and scroll down to the NTDS Settings object.

    Note There may be no connections listed here, or there may be manually created connections.

  4. Create a connection object, and give it the same name as the default object. For example, name the object RODC Connection (FRS).

  5. Edit the new connection in Adsiedit .msc or by using the Dssite.msc Attribute Editor tab. Navigate to the options attribute, and then enter 0x40 in the Value field.



  6. Repeat steps 4 and 5 to create more connections, as necessary.
  7. Force Active Directory replication outbound from this DC to the RODCs, or wait for convergence to occur. When the DFSR service on the RODC sees these connections, SYSVOL begins to replicate again.

More Information

About RT (NTDSCONN_OPT_RODC_TOPOLOGY, 0x00000040)

The NTDSCONN_OPT_RODC_TOPOLOGY bit in the options attribute indicates whether the connection can be used for DRS replication (MS-DRDM). When the connection is set, it should be ignored by DRS replication and used only by FRS replication.

Note The 0x40 value is required for both DFSR and FRS. Other connections for Active Directory replication are still required separately, and they exist on the RODC locally.
Properties

Article ID: 3212965 - Last Review: Dec 22, 2016 - Revision: 1

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