mqtt TimeoutError：（WinError 10060），但是当我更改发布者PC和订阅者PC时，它可以工作

Question

while True:
    aft = datetime.datetime.now()
    mongoQry = {"time": aft.strftime("%Y-%m-%d %H:%M:%S.%f")[:-3], "Housing Input BWD Sensor": "NULL",
        "Inverter Run": "NULL",
        "Pressure Sensor": "NULL", "NGQuantity": "NULL", "RedQuantity": "NULL",
        "SilverQuantity": "NULL",
        "Alarm-Insert Disassembly Down Sensor": "NULL", "Alarm-Insert Input Up Sensor": "NULL",
        "Alarm-Housing Input Forward Sensor": "NULL", "Alarm-Housing Input Backward Sensor": "NULL"}
    strmongoQry = json.dumps(mongoQry)


    # bimongoQry = dict_to_binary(mongoQry)
    publish.single("paho/test/single",strmongoQry , hostname="192.168.0.12")
    print("Mongo success")
    sleep(1)

这是我非常简单的代码 但是pc（192.168.0.12）无法接收到 当我使用pc（192.168.0.12）将MQTT消息发送到以前是发布者的计算机时， 可以。

我还关闭了pc（192.168.0.12）的防火墙

谁会让我知道怎么了..