Cannot connect to MQTT broker on local network

[crustaceanhate]

Hey everybody,

I currently have node-red running on a Raspberry Pi Zero and so far it's been great, but I've been running into some issues connecting to an MQTT broker on my lan. I have Mosquitto v1.6.7 running on a Freebsd jail (hostname: mosquitto) on a server in my home network. A sensor (BME280 on a NodeMCU) is publishing data to this MQTT broker, and I can see the data being published successfully using MQTT Explorer running on a separate PC. For whatever reason, I cannot get the mqtt in node to connect to this broker. It just hangs with a yellow icon and connecting. Here are my settings:

I can ping mosquitto.lan from the RPi running node-red. I can also ssh into the RPi and subscribe to the messages from the command line i.e. mosquitto_sub -h mosquitto.lan -t esp/bme280/temperature and it connects successfully and displays the published temperature values. Also, if I run Mosquitto on the RPi, publish sensor data to that instead, and point the mqtt in node at it, everything seems to work. I can also connect to the test.mosquitto.org test broker from node-red. There is no security on the broker and it is set up to accept anonymous connections.

Does anybody have any suggestions?

[Trying_to_learn]

May I suggest you enter the IP number rather than the name.

Probably not important, but for the sake of eliminating this as a possible cause.

[Colin]

How did you install node red? Are you using Docker?
Stop node red and then start it in a terminal and see what it shows in the log. Paste the log here from the start. When pasting use the </> button at the top of the forum entry window.
Also look at the mosquito log on the server and see what it shows when the pi tries to connect.

[crustaceanhate]

A good suggestion, but I've tried that as well.

[Trying_to_learn]

If you are using other devices (eg: you mentioned esp/bme280) I am not sure how they are going to resolve the name.

I would again suggest you use the IP number on all devices.

What is the command you use from a terminal to send the messages? You have only shown how you are subscribing, but not publishing.

Could you copy/paste the terminal stuff you are doing?
Or screen show with the two terminals open: one publish one subscribed.

[Colin]

@Trying_to_learn

You have only shown how you are subscribing, but not publishing

The issue is that it won't connect, so whether it can publish is not relevant.

[Colin]

Also try with the legacy support checkbox selected.

[Trying_to_learn]

Yes, ok. But I would like to see what is being sent as well and what is (not) being received.

So from a terminal seeing what is being sent would/may help.

But.... I'm not expert.

[crustaceanhate]

Hey Colin, I installed it on a RPi running Raspbian GNU/Linux 10 using this guide, no Docker containers involved. Here's the log when starting it from a terminal using the node-red-pi command

Welcome to Node-RED
===================

19 Dec 11:18:59 - [info] Node-RED version: v1.2.3
19 Dec 11:18:59 - [info] Node.js  version: v12.19.0
19 Dec 11:18:59 - [info] Linux 5.4.79+ arm LE
19 Dec 11:19:04 - [info] Loading palette nodes
19 Dec 11:19:18 - [info] Dashboard version 2.24.0 started at /ui
19 Dec 11:19:21 - [info] Settings file  : /home/pi/.node-red/settings.js
19 Dec 11:19:21 - [info] Context store  : 'default' [module=memory]
19 Dec 11:19:21 - [info] User directory : /home/pi/.node-red
19 Dec 11:19:21 - [warn] Projects disabled : editorTheme.projects.enabled=false
19 Dec 11:19:21 - [info] Flows file     : /home/pi/.node-red/flows_raspberrypi.json
19 Dec 11:19:21 - [info] Server now running at http://127.0.0.1:1880/
19 Dec 11:19:21 - [warn] 

---------------------------------------------------------------------
Your flow credentials file is encrypted using a system-generated key.

If the system-generated key is lost for any reason, your credentials
file will not be recoverable, you will have to delete it and re-enter
your credentials.

You should set your own key using the 'credentialSecret' option in
your settings file. Node-RED will then re-encrypt your credentials
file using your chosen key the next time you deploy a change.
---------------------------------------------------------------------
19 Dec 11:19:22 - [info] Starting flows
19 Dec 11:19:26 - [info] Started flows
19 Dec 11:19:28 - [info] [mqtt-broker:237e7ff3.a6434] Connection failed to broker: mqtt://192.168.1.10:1883
19 Dec 11:19:44 - [info] [mqtt-broker:237e7ff3.a6434] Connection failed to broker: mqtt://192.168.1.10:1883
19 Dec 11:19:59 - [info] [mqtt-broker:237e7ff3.a6434] Connection failed to broker: mqtt://192.168.1.10:1883

The mosquitto log is showing the following error (192.168.1.8 is the ip address of the RPi)

1608379082: New connection from 192.168.1.8 on port 1883.
1608379082: Socket error on client <unknown>, disconnecting.

[crustaceanhate]

I tried this. No dice.

[crustaceanhate]

Hey @Trying_to_learn, I am publishing messages to the MQTT broker from an ESP8266, similar to what is described here. I am using the IP address of the MQTT broker (192.168.1.10) on the ESP8266, rather than the hostname. Publishing seems to work fine, but I cannot subscribe to those messages from the node-red instance running on the RPi.

[bakman2]

@crustaceanhate

Freebsd jail

And how does the pub request arrive inside the jail? Do you need some kind of port forwarding?

[Colin]

Run the install script again to upgrade node-red to the latest, there were some issues with 1.2.3, though I am not sure whether mqtt was involved. Always a good idea to do the easy things first though.

[Steve-Mcl]

If I remember right, 1.2.3 targets a version of MQTT that had issues. So updating to latest node-red should fix this.

[crustaceanhate]

Upgraded to Node-RED v1.2.6 and everything's working now. Let that be a lesson to me to always upgrade to the latest version... or at least check the patch notes.

Thanks for your help everybody!