Windows Server 2008 : Troubleshooting Replication (part 1) - Checking Replication with repadmin

Checking Replication with repadmin

One of the primary command prompt commands you can use to troubleshoot Active Directory (AD) replication issues is repadmin. It’s available on DC, and you can use it to view replication data, force replication events, and manually create the replication topology if things really go wrong.

Tip

One of the primary symptoms that indicate a problem with replication is that new users are unable to log on. Their accounts are created in AD using one DC, but when they attempt to log on using a different DC, they receive an error message indicating the username or password is incorrect. After verifying they are using the correct username and password, it’s time to break out repadmin.

repadmin includes several commands that you can use to view replication data as shown in the following table. When AD has problems with replication, these normally give clear indications that you have errors. When these come up error-free, you can be confident that your problem is not due to replication.

Note

You must run repadmin with administrative permissions.

repadmin Status and Data Commands	Comments
Show replication status. C:\> repadmin /showrepl	Displays replication status for recent inbound replication attempts. It identifies replication partners, identifies when the last replication occurred, and determines whether it was successful. Figure 1 shows the output of this command.
Summarize status of replication. C:\> repadmin /replsummary	This command summarizes the replication state and relative health of a forest. It lists the total number of replication attempts, the number of failures, and the percent of failures compared with the total.
Show highest update sequence numbers. repadmin /showutdvec dc-name naming-context C:\> repadmin /showutdvec dc1 dc=pearson,dc=pub	Replication uses Update Sequence Numbers (USN) to determine whether a DC has the most up-to-date version of an object. You can view the highest USNs for a DC with the /showutdvec switch. Note The naming-context is the distinguished name of the directory partition.
View queued replications. C:\> repadmin /queue	Shows a listing of inbound replication requests that the DC has in queue. This should normally be zero within a site (or certainly a low number). The number of items in queue between sites is dependent on the replication schedule between sites. If you replicate only once a day between sites, this queue will steadily build up into the scheduled replication time.
Show attributes of a DC. repadmin /showattr dc-name naming-context C:\> repadmin /showattr dc1 dc=pearson,dc=pub	You can display the attributes of an object. This is sometimes useful when troubleshooting replication for a specific DC. The example shows the attributes of a DC named dc1 in the pearson.pub domain. Note This shows low-level AD data similar to what you can access using the ldp GUI tool.
Show replication metadata for a DC. repadmin /showobjmeta dc-name naming-context C:\> repadmin /showattr dc1 dc=pearson,dc=pub	You can use the /showobjmeta switch to show replication metadata for a DC. The example command displays metadata for the DC named dc1 in the domain pearson.pub. Data includes the attribute ID, version number, originating and local USN, originating server’s globally unique identifier (GUID), and a date and time stamp of the update.
Show bridgehead servers. /bridgeheads [ /v] C:\> repadmin /bridgeheads /v	Shows all the bridgehead servers for each site that includes a DC. The /v switch is used for a verbose output. Note If you have only DCs in a single site, you won’t have any bridgehead servers assigned.

Figure 1. Viewing the output of the repadmin /showrepl command

Note

replmon (available in Windows Server 2003) is not included in Windows Server 2008 or Windows Server 2008 R2.