Sends a request to the Primary Domain Controller (PDC) of the current domain to synchronize the entire domain. The PDC then asks all its Backup Domain Controllers (BDCs) to synchronize their databases with that of the PDC. This synchronization is "smart" as only the changes since the last synchronization are requested.
To check if the synchronization has been successful, look at the system log of the Event Log on the PDC and BDCs
Dim ServerMgmt As IDomainServerManagement
'Get the IDomainServerManagement interface for domain object
Set ServerMgmt = GetObject ("NTDS://DomainName")
'Synchronize the domain "DomainName"