From time to time I need to force sync all of my GCs aka DCs. This is a quick way to force everyone to replicate. If you have a lot of GCs this could take a while.
Syntax: repadmin /replicate destination_dsa Naming Context /allsources
Example: repadmin /replicate server1.test.com dc=test,dc=com /allsources
Destination server Name: server2.test.com
Naming Context: dc=test,dc=com (Domain partition)