This post outline the proper steps to move from an unsupported one-way replication deployment when using DFSR from Windows 2003 R2 and Windows 2008 to a supported configuration of two-way replication. Starting with Windows 2008 R2 we will now have Read Only replicas support in DFSR. Details of this feature can be found here. To successfully recover from a one way replication deployment we must force the downstream server to perform an Initial Synchronization and Initial Replication of the RF so that all queued changes on the Downstream server are discarded.

Full Article: DS Blog