ADs no longer synchronized

Issue

AD directories are no longer synchronized.

When modifying an AD directory attribute (e.g. 2008r2), you get the message:

The FSMO role ownership could not be verified because its directory partition has not replicated successfully with at least one replication partner.

Resolution

Force AD directory synchronization by running the windows command Repadmin /syncall DC_name /APed on a DC

See also

http://blogs.technet.com/b/askds/archive/2009/07/01/getting-over-replmon.aspx