One address is the home address for the VM itself, which it uses to communicate with the rest of the network or, if accessed publicly, the Internet. The second IP address will be available for the local data center.

"The trick is to keep these mappings between the two address spaces," said Bill Laing, Microsoft corporate vice president for the server and cloud division, in a subsequent interview.

Microsoft is not alone in offering this capability. VMware, in its VXLAN offering, also offers the ability. This solution, however, requires Cisco networking gear using the Overlay Transport Virtualization (OTV) technology.

Long-distance live migration has been a research topic in the virtualization community for several years, though it is useful only in a limited number of situations, said Chris Wolf, a Gartner research vice president covering virtualization.

Replicating a VM memory state over long distances can take a considerable amount of time, Wolf noted. It could be handy for emergency situations, such as when a data center is threatened by an upcoming flood or hurricane, and its contents must be moved to another facility. But, given the sizes of most data center-run systems, it is likely that only a handful of VMs would be moved in time.