"Open vSwitch, the open source virtual switch that was added
with XenServer 5.6 Feature Pack 1as an option is now the default
switch with XenServer 6.0.
"These virtual switches can be ganged up across hypervisors to
create a distributed virtual switch akin to the vSwitch created by
VMware for its ESXi hypervisor. See also the Nexus 1000V, made by
Cisco for its 'California' Unified Computing Systems as a
replacement for VMware's vSwitch, and speaking NX-OS like Cisco
network admins like."