hello there,
I want the servers to automatically connect together so if they reboot or the internet connection is lost and then reconnected the VPN is automatically re-established without any user intervention required.
you can use openvpn as a SERVICE and configure it to start automatically on server/client start up.
I obviously want Site A to be able to use resources on the Site B network and vice versa BUT I want to ensure that all other traffic is routed directly out of the local internet connection e.g. any traffic from Site A not destined for Site B is routed as if the VPN didn’t exist.
this is purely routing issue...
short answer, you can configure openvpn to route whatever traffic you want,
in your case ONLY lan to lan traffic.
Michael.