Tuning UDP-based connections

In this recipe, we focus on some of the basic techniques for optimizing UDP-based VPN tunnels. These techniques need to be applied with care, as there is no fool-proof method for optimizing OpenVPN performance. The actual performance gain varies with each network setup. Therefore, this recipe only shows some of the configuration directives that can be used for this optimization.

Getting ready

We use the following network layout:

Install OpenVPN 2.0 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, Client-server IP-only Networks. In this recipe, the server computer was running CentOS 5 Linux and OpenVPN 2.1.1. The client was running Fedora 13 Linux and OpenVPN 2.1.1. Keep the configuration file basic-udp-server.conf from the Chapter 2 recipe Server-side routing at hand, as well as the client configuration file basic-udp-client.conf from the same recipe...