Replica Creation is in Progress - DPM

Issue:
Data Protection Manager (DPM) hangs at "Replica Creation is in Progress" window. 

Solution/Workaround:
Disable TCP Chimney Offload. You can use the following command:

netsh int tcp set global chimney=disabled

You can see the details in one of my previous blogs…..

(http://santhoshsivarajan.blogspot.com/2009/12/tcp-chimney-offload.html)

The TCP Chimney Offload is a useful networking technology.  It allows to transfer the work load from CPU to a Network adaptor during the network data transfer. This helps improve the processing of network data on your computer or server without the need for additional programs or any loss to manageability or security. 

But sometimes you run into issues with various applications if this option is enabled.  Recently, I have experienced a very slow performance on a DPM 2007 server.  My solution was to disable the TCP Chimney Offload properties.   You need to enable or disable the TCP Chimney Offload option inside OS and Network adaptor properties.  This option will work only if it is enabled or disabled  in both locations. 

You can see the details of TCP Chimney Offload enabling and disabling procedure in the following KB article: 
http://support.microsoft.com/kb/951037