def eth_addr(f):
    """eth_addr

    :param f: eth frame
    """
    data = "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x" % (f[0],
                                              f[1],
                                              f[2],
                                              f[3],
                                              f[4],
                                              f[5])
    return data