The networking configuration is the same. It does not matter if its a internal or external IP and if you rent a server or vps, then the network is already configured corrctly so you should not alter it. A VPS is a general term, while openVZ is a specific virtualisation technology. So your question is as if you would say " I have a car" does the repair instructions for a "Volkswagen Golf IV" apply to me. So as long as you dont tell us which virtualisation technology is used for your vps, nobody can tell you if this applies to your setup.
Thanks, My ISP uses KVM software, so I guess it does not apply to me. Is it a problem to leave my networking settings the way they are now? It all seems to be working fine.