def invalid_node_ids_error(node_ids):
    """
    Return validation error string given when node_ids are not part of CLB

    :param ``list`` node_ids: List of int node_id
    :rtype: ``str``
    """
    nodes = ','.join(map(str, sorted(node_ids)))
    return 'Node ids {0} are not a part of your loadbalancer'.format(nodes)
