Management

The data networks that we use in our everyday lives to learn, play, and work range from small, local networks to large, global internetworks. At home, you may have a router and two or more computers. At work, your organization may have multiple routers and switches servicing the data communication needs of hundreds or even thousands of PCs.

In the previous chapters you discovered how routers are used in packet forwarding and that routers learn about remote networks using both static routes and dynamic routing protocols. You also know how routes to remote networks can be configured manually using static routes.

This chapter introduces dynamic routing protocols, including how different routing protocols are classified, what metrics they use to determine best path, and the benefits of using a dynamic routing protocol.

Dynamic routing protocols are usually used in larger networks to ease the administrative and operational overhead of using only static routes. Typically, a network uses a combination of both a dynamic routing protocol and static routes. In most networks, a single dynamic routing protocol is used, however there are cases where different parts of the network may use different routing protocols.

Since the early 1980's, several different dynamic routing protocols have emerged. In this chapter we will begin to discuss some of the characteristics and differences in these routing protocols, however this will become more evident in later chapters when we discuss several of these routing protocols in detail.

Although many networks will only use a single routing protocol or use only static routes, it is important for a network professional to understand the concepts and operations of all the different routing protocols. A network professional must be able to make an informed decision regarding when to use a dynamic routing protocol and which routing protocol is the best choice for a particular environment.

The Evolution of Dynamic Routing...