--- deprecations: - The ``network_device_mtu`` option in Nova is deprecated for removal since network MTU should be specified when creating the network with nova-network. With Neutron networks, the MTU value comes from the ``segment_mtu`` configuration option in Neutron. other: - The Neutron network MTU value is now used when plugging virtual interfaces in nova-compute. If the value is 0, which is the default value for the ``segment_mtu`` configuration option in Neutron before Mitaka, then the (deprecated) ``network_device_mtu`` configuration option in Nova is used, which defaults to not setting an MTU value.