The vShield VXLAN virtual wire is a layer 2 overlay network segment that enables a scalable network segment that is not tied to any physical network fabric. A VXLAN virtual wire can span multiple distributed switches to provide a virtual layer 2 network between multiple vSphere clusters.

The power of VXLAN virtual wires is the ability to implement a layer 2 segment on top of the existing layer 3 networks through encapsulation, which allows traffic to traverse geographically dispersed clusters. This is particularly useful in a cloud design where a physical layer 2 network does not exist between datacenters. A virtual wire allows a network shortcut between distributed virtual switches located on two completely separate physical and virtual infrastructures that are managed by the same vCenter. By allowing application traffic at layer 2 between clusters, VXLAN virtual wires provide the capability to vMotion virtual machines from one cluster to another. Placement on a underutilized...