From the Identity Synchronization for Windows Console, specify a preferred master and secondary master servers for the suffix to be synchronized. (Review Creating a Sun Java System Directory Source)
You do not have to provide information about other Directory Servers in your topology.
Prepare the preferred master and secondary master servers from the Console or using the idsync prepds command line utility. (Review Preparing Sun Directory Source
If you use the command line utility, you should prepare both servers in a single invocation by specifying arguments for both the preferred and secondary servers.
Install the Directory Server Connector for the suffix replicated between these directories. (ReviewInstalling the Directory Server Connector)
Configure the Directory Server Plug-in on the preferred master, the secondary masters, and every other Directory Server instance that manages users in the replicated suffix (Review Using dspluginconfig)