"OpenVPN is an easy-to-use open source VPN software based on SSL
(Secure Sockets Layer) that offers cross-platform interoperability.
The majority of OpenVPN tutorials I've found describe how users can
connect to a corporate network from their laptops over insecure
networks, such as the wireless network in a hotel. By contrast, the
setup I'm about to describe is better suited for permanently
connecting entire networks--for example, branch offices to the
headquarters of a company.
"For this setup I'll assume that you have two networks, A and B,
in different locations, both connected to the Internet with