Knowledge

DNS_ERROR_DP_ALREADY_ENLISTED - 9904 (0x26B0)

This DNS server is already enlisted in the specified directory partition.

Updated: Feb 21, 2026

Technical Background

The DNS_ERROR_DP_ALREADY_ENLISTED error code, with the numeric value of 9904 and the hexadecimal representation 0x26B0, indicates that a DNS server is already enlisted in the specified directory partition. This error typically occurs within the Windows Domain Name System (DNS) service or related APIs.

Error Details

When this error code is returned, it signifies that an attempt was made to enlist a DNS server into a directory partition that it is already part of. Enlisting a DNS server in a directory partition involves associating the server with specific Active Directory objects for management and configuration purposes.

Common Causes

  • Incorrect Usage Context: The operation was attempted on a DNS server that is already enlisted in the specified directory partition.
  • Duplicate Enlistment Attempts: Multiple attempts to enlist the same DNS server into the same directory partition without proper disengagement.

Real-World Context

This error can occur during administrative tasks such as managing DNS servers within an Active Directory environment. It is important for administrators to ensure that operations are performed in a context where the DNS server's current state and configuration are fully understood.

Is This Error Critical?

The criticality of this error depends on the specific operation being attempted. If the goal was to enlist the DNS server, then this error indicates that the operation is not necessary or cannot be completed as intended. However, if the intention was to perform a different administrative task, such as modifying settings within an existing enlistment, the error may indicate a need for further investigation.

How to Diagnose

  1. Review Operation Context: Verify the current state of the DNS server and its enlistment status in Active Directory.
  2. Validate Parameters: Ensure that the parameters passed to the API or command are correct and appropriate for the operation being attempted.
  3. Confirm Object Types: Confirm that the DNS server is correctly identified and associated with the intended directory partition.
  4. Verify Input Data: Check if any input data, such as configuration settings, are valid and consistent with the current state of the DNS server.
  5. Check Limits or Constraints: Ensure that there are no system limits or constraints that could prevent the operation from being completed successfully.

How to Resolve

  1. Correct Parameter Usage: If the error is due to incorrect parameters, ensure that all necessary and correct parameters are provided for the operation.
  2. Adjust Operation Context: If the DNS server is already enlisted in the specified directory partition, consider whether the intended administrative task can be performed without re-enlisting.
  3. Restore Data: In some cases, restoring data or configuration settings to a known good state may resolve issues related to incorrect enlistment.
  4. Retry Operation with Valid Inputs: Attempt the operation again with valid and appropriate inputs if the issue is due to transient conditions or user error.

Developer Notes

Developers should be aware that this error code indicates an attempt to perform an operation on a DNS server that is already enlisted in the specified directory partition. This can occur during various administrative tasks, such as managing DNS servers within Active Directory environments. Proper handling of this error requires understanding the current state and configuration of the DNS server.

Related Errors

  • DNS_ERROR_DP_NOT_FOUND: Indicates that the specified directory partition could not be found.
  • DNS_ERROR_DP_ALREADY_ENLISTED: Indicates that a DNS server is already enlisted in the specified directory partition.
  • DNS_ERROR_DP_NO_SUCH_OBJECT: Indicates that an object within the directory partition does not exist.

FAQ

Q: What does the DNS_ERROR_DP_ALREADY_ENLISTED error mean?

A: This error indicates that a DNS server is already enlisted in the specified directory partition, and thus the operation cannot be completed as intended.

Q: How can I resolve this error?

A: Ensure that the parameters are correct and appropriate for the operation being attempted. If the DNS server is already enlisted, consider whether the intended administrative task can be performed without re-enlisting.

Q: Is this error critical?

A: The criticality of this error depends on the specific operation being attempted. If the goal was to enlist the DNS server, then this error indicates that the operation is not necessary or cannot be completed as intended.

Summary

The DNS_ERROR_DP_ALREADY_ENLISTED error code (9904, 0x26B0) in Windows indicates that a DNS server is already enlisted in the specified directory partition. This can occur during various administrative tasks and requires careful consideration of the current state and configuration of the DNS server. Proper handling involves understanding the operation context and ensuring correct parameter usage.