Traffic shaping

In this recipe, we will use traffic shaping to limit the upload speed of an OpenVPN client. This can be used to throttle the bandwidth of a client to the server, or from client to client. Note that OpenVPN traffic shaping cannot be used to throttle the download speed of OpenVPN clients. Throttling download speeds can best be achieved using external traffic control tools, such as the 'tc' utility on Linux, which is part of the LARTC package.

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. For this recipe, the server computer was running CentOS 5 Linux and OpenVPN 2.1.1. The client was running Windows XP SP3 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...