4.13 NSX Logical Switches
A logical switch is mapped to a unique VXLAN, which encapsulates the virtual machine traffic and carries it over the physical IP network. Logical switches are isolated by nature within the cloud platform. Each logical switch is its own L2 broadcast domain. A cloud consumer or provider can create logical switches that span their area of the infrastructure within the transport zone. As the logical switch is expanded across the transport zone, and inherently, the distributed virtual switch and clusters, this enables the virtual machine to be moved across the data center with VMware vMotion®.
The NSX Controller cluster controls logical switches and maintains information about virtual machines, ESXi hosts, logical switches, and VXLANs.
The control plane mode decouples NSX for vSphere from the physical network and handles the broadcast, unknown unicast, and multicast (BUM) traffic within the logical switches. All logical switches created within the transport zone inherit VMware NSX transport zone settings. (This behavior can be overwritten by the customer.) Other options to consider when designing the logical switch control plane are described in following sections.