One common task I have to perform in Active Directory very often is forcing replication between two domain controllers. By default, replication occurs automatically between the designated bridgehead servers at each site. This time interval can vary depending on the number of sites, how the sites are linked, connection speed between sites, etc. and can range from less than a minute to several minutes.
However, there are times when you make a change on one domain controller and you want it to be immediately updated on all other domain controllers in your environment. Maybe you’ve added a new user who is waiting to login, but the user resides in another site other than the one you are working on.
Force Replication Between Domain Controllers
You can force replication to occur between two domain controllers by following the steps below:
Step 1: Open Active Directory Sites and Services.
Step 2: Expand Sites and then expand the site name that contains the server that you want to force replication. Expand the server name and click on NTDS Settings.
Step 3: In the right-hand pane, right-click on the server you want to replicate with the other servers in the site and choose Replicate Now.
That’s it! Group Policy and Active Directory data will now be replicated immediately to all of the other domain controllers that have site links to this server. Note that you can also use command line tools to force replication between domain controllers. The two commands are repadmin and replmon.
Repadmin does several things including checking the replication consistency between replication partners, monitoring replication status, and displaying replication metadata. Replmon displays the replication topology, monitors replication status including Group Policies, and more.
For example, the following command will immediately for replication to all domain controllers in the domain:
repadmin /syncall /AdeP
You have to install the Windows Support tools in order to use the command line tools to force replication. For more information about repadmin, check out the Technet article. They also have a page full of repadmin examples. Enjoy!