Redirecting the default gateway

A very common use of a VPN is to route all of the traffic over a secure tunnel. This allows one to safely access a network or even the Internet itself from within a hostile environment (for example, a poorly protected, but properly trojaned Internet caféteria).

In this recipe, we will set up OpenVPN to do exactly this. This recipe is very similar to the Server-side routing recipe, but there are some pitfalls when redirecting all of the traffic over a VPN tunnel.

Getting ready

The network layout used in this recipe is the same as in the Server-side routing recipe.

This recipe uses the PKI files created in the first recipe of this chapter. Install OpenVPN 2.3.9 or higher on two computers. Make sure the computers are connected over a network. For this recipe, the server computer was running CentOS 6 Linux and OpenVPN 2.3.9 and the client was running Fedora 20 Linux and OpenVPN 2.3.9. Keep the server configuration file, basic-udp-server.conf, at hand along with the...