Repadmin is a cmd application for diagnosing AD replication issues. Via Repadmin it is easy to view replication topology for every domain controller. And use this knowledge to manually change it and initiate replication communications between controllers. With Repadmin you can easily check replication metadata and relevance vectors (up-to-dateness (UTDVEC)).
Repadmin.exe is a built-in feature in Windows Server environment starting from 2008. It comes with AD Directory Services role and also can be setup in client OSes like Windows 10 with RSAT. In order to use Repadmin you need to have two domain controllers with configured replication between them.
Command List
Repadmin.exe has lots of commands, lets focus on most popular ones:
- /syncall - used to synchronize a certain DC with others
- /prp - if you have a Password Replication Policy (PRP), this command helps to manage it
- /queue - Shows the current queue of replication
- /replicate - this command helps to perform replication from one DC to another
- /replsingleobj - This command is handy if you need to replicate only one certain object between DCs
- /replsummary - Shows a report of a current state of replication and health in AD
- /showattr - is used when you need to see object attributes
- /showbackup - this setting displays the last backup time
- /showrepl - If you need to know current replication status use this one
How to Get General Replication Status
Let’s start from overall state of replication, run elevated cmd.exe (start->run->cmd.exe) and type in the following command:
repadmin.exe /replsummaryThe output will show you any replication failures that exist in your AD environment.
How to Force Replication
Suppose you have replication failures and you need to force a replication after fixing networking connections failure. In elevated Command Prompt (cmd.exe) on any DC run:
repadmin.exe /syncall /ApedIn addition to /syncall command we have few flags that will synchronize all partitions (/A), using push notifications (/p), in enterprise mode across Active Directory sites (/e) using distinguished names instead of DNS names (/d).
How to Manage Inbound and Outbound Replication
It is possible to disable inbound and/or outbound replication with a possibility to reenable it later. To achieve that run the following commands in cmd under admin rights:
repadmin.exe /options DC01 +DISABLE_INBOUND_REPLDisables inbound replication on a DC01
repadmin.exe /options DC01 +DISABLE_OUTBOUND_REPLDisables outbound replication on a DC01
repadmin.exe /options DC01 -DISABLE_INBOUND_REPLEnables inbound replication on a DC01
repadmin.exe /options DC01 -DISABLE_OUTBOUND_REPLEnables outbound replication on a DC01
For example, the option to disable outbound replication is a good way to perform schema updates without the need to rebuild the entire Active Directory forest.
Conclusion
Repadmin is a powerful command-line tool that simplifies diagnosing and resolving Active Directory replication issues. It provides detailed insights into replication topology, metadata, and the health of domain controllers, allowing administrators to manually trigger replication and manage replication policies. Built into Windows Server since 2008 and available via RSAT on client OS, Repadmin is an essential utility for maintaining a healthy AD environment. By mastering its key commands, IT professionals can efficiently troubleshoot replication failures and ensure smooth synchronization across domain controllers.
FAQ
- Q: What is Repadmin and why is it important?
A: Repadmin is a built-in Windows tool used to diagnose and fix Active Directory replication problems, helping maintain consistency across domain controllers. - Q: On which systems can I use Repadmin?
A: Repadmin comes pre-installed on Windows Server 2008 and later versions and can be added to client systems like Windows 10 through RSAT. - Q: What permissions do I need to run Repadmin commands?
A: You need administrative privileges on a domain controller to execute Repadmin commands effectively. - Q: How can I check the overall replication status in Active Directory?
A: Use the command repadmin /replsummary in an elevated command prompt to view replication health and errors. - Q: How do I force replication between domain controllers?
A: Run repadmin /syncall /Aped on a domain controller with administrative rights to force synchronization across all partitions. - Q: Can Repadmin disable replication temporarily?
A: Yes, Repadmin allows disabling inbound and outbound replication on domain controllers, useful for maintenance tasks like schema updates.
