OpenVPN

Gentoo Specifics
The init script allows multiple tunnels. Decide on a name for the tunnel - eg EXAMPLE

Now create your config as /etc/openvpn/EXAMPLE.conf

You can then create more tunnels by replacing EXAMPLE with more names. Each one has its own configuration and can be stopped and started individually. The default is simply to use openvpn.conf and not symlink the service. You can of course use both methods.