Domain Controller Replication: A Quick Summary Health Check

Checking Active Directory Replication Health with repadmin

If you’re running more than one domain controller — and most organisations of any size are — it’s worth proactively checking replication health on a regular basis rather than waiting for it to surface as a symptom, such as stale group memberships, inconsistent password changes, or GPO changes that don’t show up everywhere. The quickest built-in check is the repadmin tool, run from an elevated command prompt on any domain controller:

repadmin /replsummary

This walks through every domain controller in the domain (or forest, depending on your setup) and gives you a summary of inbound and outbound replication for each, including the largest delta since last successful replication and any failures, with a percentage figure showing how many recent replication attempts succeeded. A domain controller sitting at 100% with a small, recent delta is healthy. Anything reporting failures or a large delta is worth investigating immediately — start with repadmin /showrepl against the specific DC to get the detailed error, since that will point you at the underlying cause, commonly DNS, firewall/port issues between sites, or a DC that’s been offline.

Beyond repadmin: Current AD Replication Tooling (Updated for 2026)

repadmin remains Microsoft’s current recommended built-in tool for this check — it’s unchanged and fully supported on Windows Server 2025 domain controllers, with no deprecation notice attached. If you’ve previously reached for the GUI “AD Replication Status Tool” (ADREPLSTATUS) for a friendlier view of the same data, be aware it’s no longer officially maintained by Microsoft — the only version still floating around is an unofficial community fork on GitHub, not a Microsoft-supported download, so treat it accordingly. For scripting or scheduled health checks, the PowerShell cmdlets Get-ADReplicationFailure and Get-ADReplicationPartnerMetadata are current, well-documented alternatives that pair naturally with repadmin — useful when you want structured objects to feed into a monitoring script rather than parsing console text output.

Resources

• Active Directory