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IoT Hub MQTT Broker closes connection from Qt MQTT client RRS feed

  • Question

  • We have written some MQTT client using the Qt libraries and want to connect to some customers IoT Hub via its MQTT Broker TLS interface. This works correctly using some third-party MQTT client (e.g. MQTT.fx). However, we currently fail to connect with our own client. We created network traces to compare the succeeding connection to the failing, but as the connection is TLS-secured, we cannot find out the reason for the IoT Hub Broker to shut down the connection attempt by our client. The only difference in the network trace, that I can see is, that after the brokers' "Server Hello" message our client answers with "Certificate, Client Key Exchange, Change Cipher Spec, Encrypted Handshake Message" compared to the working MQTT.fx client, which only answers with "Certificate, Client Key Exchange". Both clients use TLSv1.2 and the very same connection configuration.
    Wednesday, May 6, 2020 9:09 AM

All replies

  • Hi dhoegerl,

    Thanks for reaching out to us.

    We see that you have created a support request and we hope that your issue will be resolved with 1:1 support. Also please share the resolution here once your issue is resolved, which will help other community members.


    Thanks & Regards ^Satish Boddu -MSFT Azure CXP Community

    Thursday, May 7, 2020 5:51 PM
  • Hello dhoegerl,

    We see that your blocking issue is being resolved by "Rewriting the whole client code using another MQTT client library, with which the connection seems to work fine."

    Please let us know if you need further assistance in this mater.


    Thanks & Regards ^Satish Boddu -MSFT Azure CXP Community

    Monday, May 11, 2020 3:46 PM