# STM32L4 Discovery Kit - Cannot connect to MQTT broker

**URL:** <https://forums.freertos.org/t/stm32l4-discovery-kit-cannot-connect-to-mqtt-broker/8877>\
**Category:** AWS\
**Created:** [November 7, 2018, 5:20am UTC](https://forums.freertos.org/t/stm32l4-discovery-kit-cannot-connect-to-mqtt-broker/8877 "2018-11-07T05:20:46Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\
**Post date:** [November 7, 2018, 5:20am UTC](https://forums.freertos.org/t/stm32l4-discovery-kit-cannot-connect-to-mqtt-broker/8877/1 "2018-11-07T05:20:46Z")

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**[Bread](https://forums.aws.amazon.com/profile.jspa?userID=461945)** wrote on November 07, 2018:

My board cannot connect to MQTT broker.  
So I tried to remove USE\_OFFLOAD\_SSL  
Let me know where USE\_OFFLOAD\_SSL is defined

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**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\
**Post date:** [November 8, 2018, 11:44am UTC](https://forums.freertos.org/t/stm32l4-discovery-kit-cannot-connect-to-mqtt-broker/8877/2 "2018-11-08T11:44:48Z")

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**[Bread](https://forums.aws.amazon.com/profile.jspa?userID=461945)** wrote on November 08, 2018:

Why does deleting USE\_OFFLOAD\_SSL cause the program to work?

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**Author:** ![aggarg](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/aggarg/32/4245_2.png) [@aggarg](https://forums.freertos.org/u/aggarg)\
**Post date:** [November 8, 2018, 6:00pm UTC](https://forums.freertos.org/t/stm32l4-discovery-kit-cannot-connect-to-mqtt-broker/8877/3 "2018-11-08T18:00:04Z")

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**[Gaurav-Aggarwal-AWS](https://forums.aws.amazon.com/profile.jspa?userID=447386)** wrote on November 08, 2018:

When USE\_OFFLOAD\_SSL is deleted TLS is done in Software on the main MCU as opposed to offloading it to the WiFi module. As I mentioned before, you should not need to delete USE\_OFFLOAD\_SSL in order to make the demo work.

Would you please share the logs without removing USE\_OFFLOAD\_SSL to help us better understand the problem.

Thanks.

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<div class="post-metadata">

**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\
**Post date:** [November 10, 2018, 11:22am UTC](https://forums.freertos.org/t/stm32l4-discovery-kit-cannot-connect-to-mqtt-broker/8877/4 "2018-11-10T11:22:17Z")

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**[Bread](https://forums.aws.amazon.com/profile.jspa?userID=461945)** wrote on November 10, 2018:

Is the Wi-Fi module that is not updated unable to perform SSL properly?

what is the reason?

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**Author:** ![aggarg](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/aggarg/32/4245_2.png) [@aggarg](https://forums.freertos.org/u/aggarg)\
**Post date:** [November 12, 2018, 8:47am UTC](https://forums.freertos.org/t/stm32l4-discovery-kit-cannot-connect-to-mqtt-broker/8877/5 "2018-11-12T08:47:40Z")

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**[Gaurav-Aggarwal-AWS](https://forums.aws.amazon.com/profile.jspa?userID=447386)** wrote on November 12, 2018:

Some issues have been fixed in the WiFi module and therefore it is necessary to update the module’s firmware to successfully connect to AWS IoT. Offloading SSL to the WiFi module results in better performance and smaller memory footprint. It is therefore recommended to keep USE\_OFFLOAD\_SSL enabled.

Thanks.

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<div class="post-metadata">

**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\
**Post date:** [November 13, 2018, 4:39pm UTC](https://forums.freertos.org/t/stm32l4-discovery-kit-cannot-connect-to-mqtt-broker/8877/6 "2018-11-13T16:39:15Z")

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**[Bread](https://forums.aws.amazon.com/profile.jspa?userID=461945)** wrote on November 13, 2018:

Very Very Very Thank you so much  
i never forget your help