IoT core connection with MQTT explorer

Question

Hi
I was trying to access the IoT core broker with MQTT Explorer. I can't connect to it somehow ? 
i've been using: mqtt://****-ats.iot.eu-west-3.amazonaws.com:8883 
and insert the client cerftificates in to the mqtt explorer but somehow that doesn't seem to work ? Does someone has any expierence with this ? Because i have no clue what i'm doing wrong at the moment.

Answer

MQTT Explorer subscribes by default to `$SYS/#` topic. This topic is not supported by AWS IoT Core and will cause the broker to disconnect the client.

To fix, open the Advanced settings and remove the `$SYS/#` topic from the subscription list by clicking onto it.
Ensure also the the clientId you are using to connect is allowed by the AWS IoT Policy attached to the certificate

This is the setup in the main window:

![Enter image description here](/media/postImages/original/IMk05GyANSQBOJYT1SEXVaXA)

Answer

Hi! can you provide a little bit more detail of you setup ? With the information you give I can think of two options : 
* Have you chained the Amazon Root CA with your clients certificate ? You can have a look 
```
https://docs.aws.amazon.com/iot/latest/developerguide/server-authentication.html#server-authentication-certs
```
* Is the certificate active ? Is it associated with the correct policy with the needed permissions ?

IoT core connection with MQTT explorer

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