In the course of this book we have already invoked
openvpn several times from a command line. As a first example, we built a tunnel with a pre-shared key and a rather simple configuration file. Even though there are some other parameters set in the standard configuration file we used, the easiest command to start a tunnel with a static key is:
vpnserver:/etc/openvpn# openvpn --remote <IP of System B> --dev tun1 --ifconfig 10.3.0.1 10.3.0.2 --secret /etc/openvpn/key.txt
You see, it's very easy to connect two systems with an
openvpn tunnel, when we know their IPs. All we need is a pre-shared key, a tunnel IP, and a decision on which device type to use.
If the second tunnel endpoint is a Linux system already provided ...