I have read "How to configure an Ubuntu server so that all traffic goes through a VPN?" and found it doesn't apply to my case. I am only interested in the client-side of the VPN connection as I am a customer of a commercial VPN service provider.
I wish to route all network traffic through my VPN connection so that when it drops for whatever reason, all internet access is immediately terminated.
How do I go about configuring Ubuntu 12.10?