RoPieee bridge over VPN

I have 2 networks connected via VPN and my Roon server setup on a QNAP TS-673A (Roon server version 1.8 build 844) in one of the networks. I have RoPieee 4.017 (kernel 5.10.76-1-SPCKFSH-v7l) installed on a Raspberry Pi 4B ver 1.4. The RoPieee bridge is connected to a RHA DACAMP L1 headphone amplifier via USB. The RoPieee-RHA combo is promptly recognized as an end point, both with wire or wirelessly, when connected to the same subnet as the NAS, but cross-subnet recognition failed (no such device show up in the Roon Setting->Audio section). The RoPieee is accessible through http://ropieee.local. Roon otherwise works perfectly across subnets using other devices such as mobile phones and DAP. Any idea to fix this cross-subnet recognition issue?

Are you sure the mobile devices are cross subnet? What is their IP?

Officially roon isn’t supported over a vpn.

However with help here I have it working (with Softether in my case)

Lots of discussions on the forum eg

Sure. The subnets are and IP of each device can be seen in the DHCP client lists of the two VPN routers.

I think you’ll need to forward some additional ports. You should be able to find the details in the vpn link above.

My guess (and it is a guess) is that the subnet mask may need adjusting. If you leave it as DHCP then the subnet mask may be automatically set to Maybe it needs to be

All right, after some more exploration, it seems that the Roon server is able to detect the Ropieee bridge over VPN (it is shown in Setting->About) but is unable to recognize the attached end point device. I also tried a CA DacMagic 200M with no luck. The same problem happens to the default audio output of a laptop in the non-NAS subnet (the laptop is detected but not the audio output). No recognition even the RoPieee-DacMagic combo is connected to the NAS subnet.

In summary, RoPieee-RHA DACAMP works in the same subnet but not across subnets while RoPieee-DacMagic doesn’t work in both scenarios. It is strange given that RHA DACAMP is a much older device, and DacMagic 200M is claimed to be “Roon tested”.

Has anyone found a way to build a RaspberryPi that connects over OpenVPN from any remote location to a Core at home, is recognised as a playing device and can be controlled by a phone or tablet over the same VPN? Is there a way to build something that would load an OpenVPN client and then RopieeXL? Or another neat solution? Need something fool proof that works without too much distraction. Have full control of the home network but not of the remote network which is more or less open and to which the Raspberry would connect.