def _listify_ips(ip_str):
    """Breaks a string encoding a list of destinations into a list of
    destinations

    Args: 
        ip_str (str): A list of destination hosts encoded as a string

    Returns:
        list: A list of destination host strings
    """
    if ip_str.startswith('['):
        return [x.strip() for x in ip_str.lstrip('[').rstrip(']').split(',')]
    return [ip_str]