A transport zone defines the scope of a VXLAN logical switch. It consists of one or more vSphere clusters. Transport zones can be created manually. However, vCloud Director automatically creates for each provider VDC one transport zone, which matches the clusters that are added to the provider VDC and associates it with a VXLAN network pool. When the organization VDC is created by the vCloud system administrator or from a VDC template, a network pool must be assigned—all organization VDC and vApp networks will span the transport zone scope.