'Returns the fip_cidr set for centralized floatingips.'

def _get_centralized_fip_cidr_set(self):

    interface_name = self.get_snat_external_device_interface_name(self.get_ex_gw_port())
    device = ip_lib.IPDevice(interface_name, namespace=self.snat_namespace.name)
    return set([addr['cidr'] for addr in device.addr.list()])
