---
features:
  - Add flannel's host-gw backend option. Magnum deploys cluster over a
    dedicated neutron private network by using flannel. Flannel's host-gw
    backend gives the best performance in this topopolgy (private layer2) since
    there is no packet processing overhead, no reduction to MTU, scales to many
    hosts as well as the alternatives. The label "flannel_use_vxlan" was
    repurposed when the network driver is flannel. First, rename the label
    flannel_use_vxlan to flannel_backend. Second, redefine the value of this
    label from "yes/no" to "udp/vxlan/host-gw".