def is_multicast(mac):
    """Whether a MAC address is IPV4/V6 multicast address.

    See https://en.wikipedia.org/wiki/Multicast_address#Ethernet

    ARgs:
        mac (str): MAC address

    Returns:
        bool

    >>> is_multicast('01:80:C2:00:00:08')
    True

    """
    octet = int(mac.split(':')[0], base=16)
    return octet & 1 > 0
