Large Scale Network Design LiveLessons takes you through the concepts behind stable, scalable, elegant network design, including modularity, resilience, layering, and security principles. This livelesson will focus on traditional distributed link state, distance vector, and path vector routing protocols, as well as the basic principles of centralized control planes (such as OpenFlow). A special point will be made of sorting out the relationship between policy and reachability, and where they can best be managed in a large scale network.