I am also (mostly) trying to acheive this. I don't need traffic to fail but I'm aiming to simply route all traffic from LAN clients over an OpenVPN tunnel that goes out the WAN to a VPN provider and then on to the general internet from there. Does anyone have a tutorial on how to do this? I've seen a few pfsense ones but they don't translate well into OPNSense. Any suggestions would be most welcome. I'm pretty sure it should be easy. But can't seem to make it work. Kai