US Patent 7802000 Virtual network in server farm

A plurality of virtual machines execute on a network of physical computers. The virtual machines are deployed in fenced and unfenced configurations across multiple physical computers. Host level virtual network devices execute on the physical computers, and intercept the virtual machine network traffic. For each fenced configuration of virtual machines, a distributed virtual switch transmits network traffic between the virtual machines deployed in that fenced configuration, and a virtual router routes network traffic between virtual machines deployed in that fenced configuration and external components.