Backup connection on lan network

[JakubSz]

Hello,
I have a simple LAN network with two devices, A:192.168.1.180 and B:192.168.1.181, connected via a wired connection. I need to create an emergency VPN connection between these two devices over the internet using the GSM network. I have two RUT200 routers.
Is it possible to configure them in this way?

Thank you all in advance,
Jakub

[Daumantas]

Hello,

The VPN connection can definitely be established. However, as they are both in the same subnet, I’d suggest using either a L2 VPN like OpenVPN TAP, or L3 VPN and address each device using their respective tunnel IPs with port forward configured.
However, the first I’d suggest trying to setup a L2 OpenVPN tunnel by following the instructions provided here: Connecting two same subnet office networks using OpenVPN bridge (TAP) - Teltonika Networks Wiki
Instead of TLS, Static Key authentication could be used. It’s much easier to setup, but a little less secure.
Let me know if you encounter any difficulties along the way!

Best regards,

[JakubSz]

Thank you for the quick response. Yes, I tried that setting. However, I’m not sure if I explained or connected it correctly. The backup connection is supposed to switch automatically between the wired network and VPN (GSM). I have try connection like in the picture. I briged all devices on routers eth0.1, eth0.2 and tap0.Sometimes it is working and sometimes not.

Best regards,
Jakub