Re: Problems with MQTT on FRDM-K64F

Paul Sokolovsky

Hello Kevin,

I don't know what may be wrong in your case, as when networking is
involved, many (e.g. a dozen of) things may be wrong. However, I may
suggest few generic ideas how to avoid common and unneeded pitfalls:

1. Start with unchanged samples and configurations. These are the
configurations intended to be run and tested by their authors and most
of other users.

2. Before starting to test a sample on a real hardware, test it with
qemu_x86 if possible.

3. Before starting with "complex" samples like MQTT, make sure that
basic samples like echo_server work for you.

4. When working with "complex" samples which involve
additional/3rd-party components, like MQTT broker in this case, make
sure first that they work as intended. E.g., mosquitto has tools to
publish and subscribe messages, you need to test your setup using them
first, including running them on a different machine than where the
broker resides. For any issues with that, you'll need to consult
mosquitto documentation and support channels.

5. When dealing networking, always keep in mind that it's a complex
matter with many "moving parts". For example, networking in modern
OSes is unalienable from the notion of "firewall". Have you configured
your firewall properly to let your MQTT broker be accessed?

On Tue, 27 Jun 2017 13:41:49 +0000
Kevin Stöckl <> wrote:


I try to run the sample mqtt publisher on the frdm-k64f.

First I changed the IP-adress on the linux host machine to

Then i type make BOARD=frdm_k64f and then I try to run mosquitto with
sudo mosquitto -v -p 1883.

There I got the error message Address already in use and nothing

In the config.h File I changed the Server Address to

What could be the problem?

How can I change the IP-adress of the board? And is this necessary?

Thanks in advance


Best Regards,
Paul | Open source software for ARM SoCs
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