Network Virtualization Gets Physical
Network virtualization, as others have noted, is now well past the hype stage and in serious production deployments. One factor that has facilitated the adoption of network virtualization is the ease with which it can be incrementally deployed. In a typical data center, the necessary infrastructure is already in place. Servers are interconnected by a physical network that already meets the basic requirements for network virtualization: providing IP connectivity between the physical servers. And the servers are themselves virtualized, providing the ideal insertion point for network virtualization: the vswitch (virtual switch). Because the vswitch is the first hop in the data path for every packet that enters or leaves a VM, it’s the natural place to implement the data plane for network virtualization. This is the approach taken by VMware (and by Nicira before we were part of VMware) to enable network virtualization, and it forms the basis for our current deployments.
In typical data centers, however, not every machine is virtualized. “Bare metal” servers — that is, unvirtualized, or physical machines — are a fact of life in most real data centers. Sometimes they are present because they run software that is not easily virtualized, or because of Continue reading
