KNX Bridge declaration for KNX-IP-devices

Hello there,

how is the KNX bridge declaration for an IT-only KNX device supposed to be written in a things file?

Because IP-only devices sit on their own line (regarding KNX topology) without an IP-Router, it seems a bit strange to define an KNX Bridge (in reality this a KNX IP-Router), which might be located in a different line, just to satisfy things syntax.

Imagine this scenario:

IP Line: 1.1

  • no 1.1.0 PA, because it’s an IP-only line in an IP backbone project *
    openHAB with a dummy PA of 1.1.2, IP address 192.168.1.2/24
    some IP-KNX device with a PA of 1.1.11, IP address 192.168.1.11/24

TP Line: 1.2
IP-Router PA 1.1.0, IP 192.168.1.20/24
1.1.x some TP KNX devices

Putting a laptop with ETS in 192.168.1.0/24 subnet, it is possible to communicate with the IP-KNX device through multicast only.

Setting the IP-Router 1.2.0 as the ETS interface, it is also possible to communicate with the IP device.

For openHAB is also sitting in 192.168.1.0/24 subnet, it also must be able to communicate with the IP device through mean of multicast - from an IP-network point of view.

So, imagine writing two different things files - one for KNX devices in line 1.1 and another one for KNX devices in line 1.2. The things file for line 1.2 needs a bridge declaration using the IP-Router 1.2.0 either as type TUNNEL or type ROUTER.

But what about the things file for line 1.1? The final device is directly reachable via multicast - BUT it ist NOT a KNX IP-Router or gateway, nor will it behave like one.

Looking forward to your answers.

Kind regards,
Carsten