Multiple IP interfaces in one XKNX instance

[ssuchter]

I'm using HomeAssistant to automate things including my KNX system. I've got two buildings that are on the same private IP network connected via a long underground Ethernet cable. Each structure has its own KNX installation with their own KNX IP interface. I've taken care to ensure that the KNX addresses used in the two structures are distinct and non-overlapping.

Unfortunately, HomeAssistant seems to have only one XKNX object, and each XKNX object seems to only take one IP configuration.

What instead I want is the combination of HomeAssistant+XKNX to utilize both IP interfaces, knowing what outgoing packets should go to which interface. (Or, I guess it could just send to both, and the "wrong" one would drop them.)

I think the easiest way to achieve this is to modify XKNX to have this multiple-destination+routing capability. (Very similar to how networking stacks utilize routing tables to decide which interface to send packets to.) Then the configuration methodology of HomeAssistant would need to be modified to somehow express this. I'd probably start with yaml configuration instead of GUI, since this is a fairly advanced use case.

Thoughts?

[farmio]

Hi 👋!
Here some thoughts about that:

• I think the easiest way to achieve what you want is to use KNX IP Routers instead of interfaces and merge the projects to a single ETS project.
• For xknx, I think connecting to multiple endpoints is out of scope since it's not a software router, but first of all a KNX IP client.
• The Home Assistant KNX integration could theoretically run multiple KNX integration instances - each having a single xknx instance with its connection to a IP interface or routing network. I wouldn't call this change easy though as it would introduce lots of breaking changes for existing users. And imho using UI-config for this would be more straightforward than yaml as it would inherently assign a config to a ConfigEntry, whereas a yaml config would need to be assigned to a ConfigEntry (connection) manually - which is error prone at best (since connection is configured in UI).

[ssuchter]

Thank you very much for your input! I will look into the KNX IP routers. They are already in a single ETS project that contains both structures (it's part of how I've ensured the addresses are all unique) so hopefully I can coax the hardware to do forwarding over the IP backplane.

Closing this because of the very helpful reply; if for some reason it doesn't seem like the right solution, I will re-open.