Programmable Networks

Initially, computer networks were something physical and static, with wires and hardware, but with advanced computation, virtualization, and connectivity, networks have become more flexible and configurable by software. In this chapter, we’re going to talk about how software has changed the picture for computer networks. We are going first to examine several different technologies used today to create networks via software, then we are going to examine the current standard technology, known as software-defined networks (SDNs).

As we saw in the first chapter, computer networks can be quite complex and difficult to maintain. There are several different sets of equipment that range from routers, switches, and NATs to load balancers and more. In addition, within each piece of equipment, there are several different types of operation, such as core or access routers. Network equipment is typically configured individually with interfaces that are very different...