I've setup OpenVPN on my Ubuntu (16.04 / OpenVPN 2.4) box to start at boot. This work in the sense that a connection gets established, but unfortunately it also seems to mess with my routing tables: I am unable to reach the box once the VPN connection is up.
My first attempt was adding another NIC to have a dedicated VPN-NIC, but as far as I can tell this isn't really an option with OpenVPN. I've also tried following this guide for setting up policy routing, but to no effect.
My last attempt so far was adding routes for local ranges in the config -file, but as far as I've understood it this is supposed to be used "in reverse" (adding routes for traffic you want redirected, not excluded).