Mosquitto MQTT broker - No connections

Configuration
1

Hi folks.

For months now I’ve had HA running on a Pi5 with Mosquitto MQTT broker accepting data from 3 Pico W devices I have. A week ago the data stopped.

This being the last valid connection:

2025-10-14 15:30:12: New connection from 192.168.0.24:62276 on port 1883.
2025-10-14 15:30:12: New client connected from 192.168.0.24:62276 as jaxxx_mqtt_client (p2, c1, k0, u'mqtt_xxxr').
2025-10-14 15:30:12: Client jxxxx2_mqtt_client disconnected.

If I now try a connection through the Pico via Thonny I get the error “OSError: [Errno 103] ECONNABORTED” when the code runs mqtt_client.connect(). The same error on all Pico devices.

I’ve rebooted all devices including the Pi/HA, checked updates, looked at the Mosquitto logs and see no attempted connections from these Pico.

I have not changed any parameters or settings within the broker.

I feel I’m missing some basic issue???

One strange thing is every 2 seconds there’s an attempted connection from a device not on my 192.168.0.0-255 network. Might be unrelated and this was happening prior to the connection failures from the 14th.

2025-10-21 16:11:16: New connection from 172.30.32.2:38532 on port 1883.
2025-10-21 16:11:16: Client <unknown> closed its connection.
2

That’s normal. It is the supervisor watchdog ( 172.30.32.x is the address range used by docker containers). You can confirm this by turning this switch off on the add-on page and those connections should stop:

image

Once confirmed turn the switch back on. It is used to restart the broker if it crashes.

Sounds like an issue with your network. Has the Home Assistant IP address changed?

Can you connect to the broker with MQTT Explorer?

1 Like
3

Thanks Tom.

Appreciate the help. Your network question prompted me to AGAIN check things and its all good, working…but…in my network is a Wi-Fi extender to which these Pico’s connect as they are outside the house. I bought my weather station Pico inside, changed the SSID it sought to the main router and things worked immediately.

Never discount the blindingly obvious!