How to discover devices on a different subnet?

I’ve set up two networks, an IoT one and a personal network. I’ve set up the Firewall rules so that from my personal network I can ping the IoT devices but not the other way round. For example, my IoT network is in the network and my personal network is in the network.

How can I get OpenHAB to discover things on a different subnet? I’ve enabled MDNS in my network if that is how OpenHAB discovers devices but to no avail.


Depending on the technology/API I don’t think you can. For a lot of these technologies they send it a broadcast notification which only goes to the subnet.

You might be able to make it work by putting you OH server on both networks and binding OH to the IOT subnet.

I did the same thing as @sonyxperiageek did. Home network is on and iot is on

Openhab 2.5 runs on docker on my nas wich is on my main network

I checked the connection between both network and TV y communicate the right way. My home network can communicate with iot but not vice versa.

Unfortunaly I don’t see and can’t conteol the devices in the iot network.

How can I gain access to them?

@rlkoshak I don’t understand how to do what you mentioned. Create a new openhab server wich is in the iot network. So then i have two openhab servers? How do I do that with docker lying on my nas wich is in the home network?

This post is old, maybe there is a new way to do it.

I do control openhab mainly with my phone, wich is in the main network. This means that a complet separate iot openhab network is not doable, right?

Thanks for the help

Your openHAB instance needs to have an network interface on both networks. You can set the primary network in the settings to the IoT network. Then openHAB should be able to send and receive the broadcast packets that are often used for discovery of devices. This of course requires that your IoT subnet to be configured so that the devices on that subnet can see each other. Otherwise openHAB can’t see the devices.

I know this is possible because others use it. But for the most part it’s a networking question, not an openHAB question. Almost all the configuration takes place outside of OH. All you do in openHAB is to select the primary subnet from the list available in MainUI (or PaperUI if still on 2.5).