In case my previous post wasn't clear:At site A (OPNsense), set the tunnel address in the local wg instance to 192.168.2.x/24 (where x must be unused at site B). Set the allowed IPs in the endpoint config to 192.168.2.0/24.At site B (AVM), do the opposite (192.168.178.x/24 / 192.168.178.0/24).Good luck.[edit] The AVM how-to seems to suggest setting the wg interface's tunnel address to the same address and subnet as the local LAN interface. Really weird. So if the above doesn't work, try this. [/edit]