It’s common to find forum questions about DFSR not replicating *.bak files.
By default DFSR has file filter on replicated folder that excludes the files with names starting ~ or files with extension *.tmp or *.bak from replication. You can change it using DFS Management Console.
– Go to ReplicationGroup.
– Click on your replication group.
– Go to Replicated Folder tab.
– Click on your replicated folder and there is a property page that will pop up. It will have file filter which you can change.