Summary

  • 2 minutes

In this module you learned that AD DS replication troubleshooting is an evidence problem, not something you resolve by running every replication synchronization command you are aware of.

Use this sequence when troubleshooting AD DS replication:

  1. Establish expected partners, schedules, and directory partitions.
  2. Preserve forest-wide and destination-specific evidence.
  3. Identify the destination, source, partition, last success, and first useful error.
  4. Test the implicated DNS, network, authentication, topology, or local-health dependency.
  5. Apply one supported correction or stop at an escalation boundary.
  6. Verify every affected relationship and the original business symptom.

Core tool reference

The following table lists the core tools in your replication troubleshooting toolkit:

Tool Primary use Risk
repadmin /replsummary Find broad source and destination failure patterns. Read-only diagnostic
repadmin /showrepl Inspect inbound partners, partitions, timestamps, and statuses. Read-only diagnostic
Get-ADReplicationFailure Query structured failure data through ADWS. Read-only diagnostic
dcdiag /test:replications Correlate partner failures with DC diagnostics. Read-only diagnostic
Resolve-DnsName Prove host, service, and GUID CNAME identity. Read-only diagnostic
Test-NetConnection Test one named endpoint and port. Read-only diagnostic
repadmin /showconn and repadmin /options Inspect connections and disabled replication. Read-only diagnostic
repadmin /replicate Test one valid source, destination, and partition after correction. Low-impact operational change

Status and event quick reference

The following table lists the status and event items that are important in replication troubleshooting:

Status or evidence Interpretation Response
Error 1722 An RPC operation failed, but the status doesn't identify whether DNS, network, endpoint, authentication, or service state failed. Test the named dependency path from the destination.
Error 1256 after an earlier source failure The destination canceled later work after the earlier failure. Investigate the first non-1256 status.
Status 8477 An isolated result means replication is in progress. Recheck it. Investigate if it persists or repeats beyond the expected schedule or operational window.
Error 8452 The named partition is being removed or the source isn't currently valid for that destination. Compare current topology and partition placement; allow expected changes to converge.
Event 1988 or error 8606 A possible lingering object was blocked. Preserve evidence and escalate assessment.
Event 2042 or error 8614 The affected inbound relationship exceeded the tombstone-lifetime protection window. Keep the safeguard in place and escalate before reconnection.
Event 2095 or DSA not writable Update sequence number rollback or another unsafe writable state is possible. Preserve evidence, isolate only when guidance requires it, and escalate supported recovery.

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