I am trying to get OpenVPN working here.
As a client only - I have zero interest in the server.
The repo version might be having problems with the fact that this is a non-systemd version of Jessie. Or rather, libsystemd IS on this system, but systemctl is *not*.
So I compiled a recent version from Git, that defaults to compiling *without* systemd, tossed it in /opt, and it seems to work..
The connections will initialize, and interact until the last step, which is typically the tun/tap switchover.
The make .configuration script seems to indicate that tun is available, but it does not seem to be working.
And I do not know enough about this problem to solve it on Linux.
There seem to be tun scripts, BUT they seem to be for the server, and I certainly do not want the system to boot into tun or remain after the client is closed. In what little I can find that issue is muddled.
On Win it is simpler. You can call TAP with a script and set the routing table (if necessary - OVPN normally handles that). OVPN also typically defaults to resetting the routing table there on exit.