I’m stumped on this one.
I have an OpenSprinkler3.0 controller that will report to an MQTT broker. I have one RPi4 with homeassistant and Mosquitto broker installed. I have a separate RPiZero with Raspbian and Mosquitto installed. I have a domain (mqtt.example.com) that directs to my router and port 1883 forwards to 1883 on the RPiZero.
If I use the WAN address (mqtt.example.com:1883) for the RPiZero, Open Sprinkler connects and sends messages to the RPiZero broker, no problem.
But using the LAN IP address (192.168.1.51:1883), it doesn’t work. Here’s the weird thing. If I put in the LAN IP for the RPi4 broker running homeassistant (192.168.1.50:1883), it connects and works fine.
I’ve tried Android and Windows MQTT clients, and they connect to both brokers fine using WAN and LAN addresses. So for whatever reason, the OpenSprinkler can connect to one RPi using MQTT broker, but not another. Other clients don’t have the same issue. Any ideas?