Hmm, that’s a good question. The iRobot webpage for Optimal firewall configurations suggests that the MQTT communication happens on port 8883:
Internal Network Traffic
- UDP port 5353/5678 for discovery.
- TCP/HTTPS 443 for data traffic.
- TCP/MQTT 8883 for data traffic.
The port number doesn’t seem to be configurable in dorita980 or rest980, but I did have some trouble connecting to it yesterday.
I’ll try again today and make sure I reset the Roomba beforehand in order to kick off any existing connections.