The performance of DFS Replication in Windows Server 2008 is slower than expected on a WAN connection, and no error message is logged in the DFS Replication log

In Windows Server 2008, the performance of Distributed File System (DFS) Replication for one or more replication groups is slower than expected. When you view the DFS Replication health report for these replication groups, or when you run the DFSRDIAG BACKLOG command against these replication groups, you notice that the number of backlog files continuously increases. Additionally, no error is logged in the DFS Replication log on the sending member.

This problem may occur for many reasons. For example, the wide area network (WAN) connection may be unstable. This problem is difficult to troubleshoot because the error condition is not logged in the DFS Replication log on the sending member.

If event ID 5014 is logged on the receiving member, this problem is more likely to be related to an unstable WAN connection.

An instance of event ID 5014 that has the error code of 1726 indicates a temporary remote procedure call (RPC) connection problem. This RPC connection problem may be caused by an unstable WAN connection. Event ID 5014 may be followed by event ID 5004. Event ID 5004 indicates that the connection is reestablished. The following is an example of event ID 5014:The RPC connection may fail because of a network problem. This problem prevents the DFS Replication service from obtaining files. For most RPC connection problems, the DFS Replication service will try to obtain the files again without logging a warning or an error in the DFS Replication log. You can capture the network trace to determine whether the cause of the problem is at the network layer. To examine the TCP ports that the DFS Replication service is using on replication partners, run the following command in a Command Prompt window: