Using a client-side up/down script

In this recipe, we will use very simple up and down scripts on the client side to show how OpenVPN calls these scripts. By logging messages to a file, as well as the environment variables, we can easily see which information OpenVPN provides to the up and down scripts.

Getting ready

Install OpenVPN 2.1 or higher on two computers. Make sure the computers are connected over a network. Set up the client and server certificates using the first recipe from Chapter 2. For this recipe, the server computer was running Fedora 12 Linux and OpenVPN 2.1.1. The client was running Windows XP SP3 and OpenVPN 2.1.1.

How to do it...

1. Create the server configuration file:

   proto udp
   port 1194
   dev tun
   server 192.168.200.0 255.255.255.0
   
   ca       /etc/openvpn/cookbook/ca.crt
   cert     /etc/openvpn/cookbook/server.crt
   key      /etc/openvpn/cookbook/server.key
   dh       /etc/openvpn/cookbook/dh1024.pem
   tls-auth /etc/openvpn/cookbook/ta.key 0
   
   persist-key
   persist-tun
   keepalive 10 60
   ...