def preferred_ip(vm_, ips):
    '''
    Return the preferred Internet protocol. Either 'ipv4' (default) or 'ipv6'.
    '''
    proto = config.get_cloud_config_value(
        'protocol', vm_, __opts__, default='ipv4', search_global=False
    )

    family = socket.AF_INET
    if proto == 'ipv6':
        family = socket.AF_INET6
    for ip in ips:
        try:
            socket.inet_pton(family, ip)
            return ip
        except Exception:
            continue
    return False