Troubleshooting Active Directory Replication

Troubleshooting Active Directory Replication

Although domain controllers generally automatically manage the replication process, there are instances when incorrect configuration settings or troublesome network connections can prevent Active Directory information from being replicated between domain controllers. There are quite a few mechanisms that can be used to monitor and troubleshoot the Active Directory replication process.

1. The tools available are:








You can also configure Active Directory event loggingThe Dsastat.exe command-line toolReplication Diagnostics Tool (Repadmin.exe)Active Directory Replication Monitor (Replmon.exe)

A few common methods that you can use to monitor or troubleshoot Active Directory replication are summarized below:

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Verify network connectivity in your environment: When Active Directory replication has stopped, verify your existing network connections. For replication to occur, your domain controllers have to be connected by capable LAN links. Using high speed links typically improves replication performance.

• Verify site links
: In order for domain controllers in different sites to exchange Active Directory data or information, you have to configure the appropriate site links. When replication is not occurring between sites, verify that a site link object does link the current site to a site which is connected to the remainder of the sites of the network.

• Verify the replication topology
: You can use the Active Directory Sites and Services console to check that your replication topology is reliable and constant. Errors are displayed in a dialog box in the console.

• Manually verify that Active Directory information has been synchronized. You should on a regular basis verify that information is synchronized between domain controllers within domains.

When replication errors are encountered, check the Directory Service event log in Event Viewer.

　

　

　

　

Active Directory replication errors are written to the Directory Service event log.

There may be instances when Active Directory replication is quite slow. A few methods of correcting this problem are summarized below:

If the configuration value specified for the frequency of intersite replication is set too low, you may experience large delays between when changes are made on one domain controller and when it is replicated on a domain controller in a different site. To fix this problem, consider changing the setting of the replication frequency.

When your existing network resources are unable to cope with the quantity of traffic being generated by Active Directory replication consider the following:

Create site link bridgesCreate site linksIf feasible, configure additional resources for Active Directory replicationIf realistic, modify the setting of the replication frequency

Having no site link bridge can result in Active Directory information taking quite a while to be replicated between domain controllers. You can create a site link bridge or you can bridge all sites. This is typically necessary when there are only site links in your network, but no site link bridges.