I have all my IoT devices on a separate VLAN. The MQTT broker is the main VLAN. A rule in the firewall allows port allows devices in the IoT VLAN to use port 1883 to communicate with the broker.
The above works for everything except the Shelly-1 relay using the ShellyMQTT. I know something is funky because when I open all ports between the Shelly-1 and the MQTT broker, the topics in MQTT Explorer are different from when I just opened 1883, AND the relay works to perfection.
Hence, the questions. What are all the ports needed between Shelly-1 and the MQTT Broker?
Thank you,
JP