VPN Hub - devices with same local IP

I’m starting out testing VPN Hubs in RMS. I’ve done an initial test with one RUT and a connected raspberry pi which has been successful.

We have multiple RUTs in the field each with a raspberry pi connected. Generally we assign the pi’s with the same local IP address (e.g. 192.169.1.2).

How do we handle these with a VPN hub? I guess we will run into conflicts? Does each device get assigned a unique IP we can use to connect to instead?

Hello,

Thank you for reaching out.

What you’re referring to is essentially VPN operation in TAP (Layer 2 bridge) mode, which would allow devices on different sites to appear within the same subnet, even with identical local IP addresses. At the moment, RMS VPN Hubs support only routed (Layer 3) LAN-to-LAN connections between networks in different subnets, and TAP mode functionality is still in beta and under development.

You can find more information about the current capabilities of RMS VPN Hubs wiki documentation here:

Alternatively, you could achieve this setup using a custom OpenVPN TAP mode configuration. In that case, the Raspberry Pis connected to different routers could reside in the same bridged network (with identical IPs if necessary).

For reference on configuring OpenVPN in TAP mode:

I hope this helps clarify the current situation and possible workarounds. If you have any further questions, feel free to reach out.

Best regards,

Thanks for your response. For TAP mode, we would need to run our own OpenVPN server correct? The other alternative is just to ensure that each RUT is configured with a unique subnet (or if using the same subnet that each device has a unique static IP?)

Hello,

Yes, for OpenVPN in TAP mode, you would indeed need to run your own OpenVPN server with a public IP address.

Regarding your question about subnets in TAP mode: since TAP mode bridges the LAN interfaces (Layer 2), both the server and clients can remain in the same LAN subnet (e.g., 192.168.10.0/24). However, it’s important that each device has a unique LAN IP address within that subnet, e.g., server: 192.168.10.1, client 1: 192.168.10.2, client 2: 192.168.10.3 and so on.

If you have any further questions, feel free to reach out.

Best regards,