Hi, I'm in the process of making a plan for moving Exchange 2010 to a new datacenter. This new datacenter is in another site, and another subnet. So far i decided on installing new servers instead of picking up the servers and change ip adress and so on. We have HA (DAG) in place and will continue to use a DAG in the new datacenter. Once everything is built in the new site the old site will be decommissioned. In my opinion there are two ways how I would get the mailbox data to the new mbx servers. 1: Build a new DAG for the new site. Make new databases and move mailboxes the old fashioned way. 2: Extend our current DAG with the MBX servers in the new site and seed databases to these servers. Once everything is done activate these databases. In other words for the purpose of transitioning there would be a temporary cross site DAG What would be the best way to go about this? What are the pros and cons? Any experience and advice is welcome.