mDNS

[tielur]

Is there any type of configuration or setup I need to do to get mDNS to work? I have a few other room assistant's running on other pi's that this add-on wont join the same cluster because it looks like mDNS is getting an error with the add-on:

2/28/2021, 4:17:09 PM - error - ClusterService: Failed to start mdns discovery (dns service error: unknown)

[mKeRix]

mDNS doesn't play well on many Home Assistant OS/Supervised setups unfortunately, I didn't find a special trick to make it work yet. We might be able to get better compatibility with a change in room-assistant itself, but that's quite a bit in the future on my timeline. Until then the workaround is just to specify at least one of the other nodes addresses in the cluster section of the Home Assistant add-on config manually. Once a connection has been made the nodes will exchange information on other peers that they know about, so it isn't absolutely needed to specify all peers (although it is recommended).

[tielur]

I'm wondering if it's something with the network layer, I assumed the home assistant plugin can communicate on the same network that home assistant is on without additional configuration?

[mKeRix]

The add-on should be configured to do any outbound communication as it pleases, but inbound communication is limited to the forwarded ports (can be changed in the add-on config UI). mDNS is special though, as it's currently using a system service on Linux devices that takes care of these advertisements... HA OS/Supervised doesn't exactly work well with that I think, although I know that they've recently done some improvements.