This Gauge32 value is an instance counter tied to the external key of a distributed virtual switch (DVS), such as a Nexus 1000V or VMware vDS, integrated with UCS, distinguishing recreated instances of the same switch identity. An admin relies on cucsVmSwitchKeyInst in the rare case a distributed virtual switch is deleted and recreated with the same external key, so UCS Manager's records don't confuse the old and new switch instances. For example, if a DVS is rebuilt in vCenter and reassigned the same key, cucsVmSwitchKeyInst still lets an admin's monitoring tell the new switch instance apart from historical data about the old one.