MQTT connection failed rc -2 Topic is solved

[Rolandet]

Hi all,

I've spent some time going through the search, so forgive me if there's already a topic for this error (and hopefully with a solution)
If not, then I hope you can help me out:

Recently installed new SD card (old one FUBAR). Installed Domoticz etc and mqtt per Jelle Peters' youtube vid

Spoiler: show

https://www.youtube.com/watch?v=w7QhsFqBr30&t=7s

. as I have done many times before (be it a long time ago)

Now the problem I have is that my LSC smart plugs (flashed to tasmota) can not connect to the broker

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Connect failed to 192.168.178.24:1883, rc -2.

I've gone over several topics, about adding/removing

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listener 1883           allow_anonymous true

. etc but I just can not get it to work

Anyone here have the golden hint, or is willing to help me debug?

I realise I may have to add some more settings here, in order to troubleshoot. Please ask, and I'll add it a.s.a.p

tnx
Roland

[ferrosk]

Hi,

By default mosquitto is running in local mode only (listening for connection on localhost interface so it is reachable only by clients running on the same host as mosquitto is running). You need to enable mosquitto to listen on your network (lan) interfaces - add this to conf:

listener 1883 0.0.0.0

but be aware that with this together with "allow_anonymous true" option you authorize connection to mosquitto from all hosts on your network without authentication so it is unsecure!

[Rolandet]

Tnx ferrosk

I'm curious, is this a new feature/setting?
Cause I've used a quite old way of setting things up (hence the reference to the YouTube vid)

[ferrosk]

It is default setting since mosquitto version 2.0.0:

https://mosquitto.org/blog/2020/12/vers ... -released/

[Rolandet]

I see. That would explain why my old rpi4 installation (mosquito v1.5.7) doesn't have this issue (to be fair, this topic is about another users setup)

[Rolandet]

Hi,

By default mosquitto is running in local mode only (listening for connection on localhost interface so it is reachable only by clients running on the same host as mosquitto is running). You need to enable mosquitto to listen on your network (lan) interfaces - add this to conf:

listener 1883 0.0.0.0

but be aware that with this together with "allow_anonymous true" option you authorize connection to mosquitto from all hosts on your network without authentication so it is unsecure!

I've gotten a little further thanks to your suggestion.

In /var/log/mosquitto/mosquitto.log I see:

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Config loaded from /etc/mosquitto/mosquitto.conf

But the device still shows the same error, like mosquitto hasn't properly read the conf file

After a reboot I see the process running:

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PID 517 /usr/sbin/mosquitto -d

Im not sure, but it looks like that would suggest the conf file is not read.

When I kill this process and restart it using sudo systemctl start mosquitto the new PID shows:

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PID 5825 /usr/sbin/mosquitto -c /etc/mosquitto/mosquitto.conf

Now it DOES allow my device to connect (and indeed I can control it from Domoticz)

So somehow the start of mosquitto after reboot doesn't seem to load the conf file
Where can I see what parameters are passed when a program is started automatically after boot?