Home Assistant can't add Matter devices that are in a different VLAN

[agners]

@agners

Alternatively: Dual-Home Home Assistant might be a solution. The Matter Server runs on “host network”, means it has access to all network interfaces of the Home Assistant instance. And the Matter SDK by default uses all network interfaces available for mDNS resolution. So, if you add Home Assistant to both networks, it should work. There is only one caveat: If you use Android for commissioning, it may share a link-local address with the Matter Server. We then have to make a guess on what network that device is

To expand a bit more on this (for those who use dual homed/multi homed approach and Android): The Matter Server has an argument --primary-interface, which gets set to what Home Assistant OS/NetworkManager considers the primary interface. To force a particular interface, another --primary-interface <vlan-interface> can be added to the recently added configuration option “Extra Matter Server arguments” to force a particular VLAN to be used.