def is_bad_port(port):
    """
    Bad port as per https://fetch.spec.whatwg.org/#port-blocking
    """
    return port in [1, 7, 9, 11, 13, 15, 17, 19, 20, 21, 22, 23, 25, 37, 42,
        43, 53, 77, 79, 87, 95, 101, 102, 103, 104, 109, 110, 111, 113, 115,
        117, 119, 123, 135, 139, 143, 179, 389, 427, 465, 512, 513, 514, 
        515, 526, 530, 531, 532, 540, 548, 556, 563, 587, 601, 636, 993, 
        995, 2049, 3659, 4045, 6000, 6665, 6666, 6667, 6668, 6669, 6697]
