Scripting and IPv6

Now that IPv6 addresses are more common, it is instructive to show how IPv6 addresses are passed from the server to client-side scripts. Basically, all environment variables that existed for IPv4 addresses also exist for IPv6, simply by appending or inserting _ipv6 to the environment variable. In this recipe, we will show you how to process these environment variables.

Getting ready

Install OpenVPN 2.3 or higher on two computers. Make sure that the computers are connected over a network. Set up the client and server certificates using the first recipe from Chapter 2, Client-server IP-only Networks. For this recipe, the server computer was running CentOS 6 Linux and OpenVPN 2.3.10., and the client was running Fedora 22 and OpenVPN 2.3.10. For the server, keep the server configuration file, basic-udp-server.conf, from the Server-side routing recipe, from Chapter 2, Client-server IP-only Networks.

How to do it...

1. Append two lines to the server configuration file, basic-udp-server...