'Plugin the interface.'

def plug_new(self, network_id, port_id, device_name, mac_address, bridge=None, namespace=None, prefix=None, mtu=None):

    ip = ip_lib.IPWrapper()
    tap_name = device_name.replace((prefix or self.DEV_NAME_PREFIX), constants.TAP_DEVICE_PREFIX)
    (root_veth, ns_veth) = ip.add_veth(tap_name, device_name, namespace2=namespace)
    root_veth.disable_ipv6()
    ns_veth.link.set_address(mac_address)
    if mtu:
        self.set_mtu(device_name, mtu, namespace=namespace, prefix=prefix)
    else:
        LOG.warning(_LW('No    MTU    configured    for    port    %s'), port_id)
    root_veth.link.set_up()
    ns_veth.link.set_up()
