Chapter 12. Switching Case Studies

What You Will Learn

This chapter examines case studies for the following:

  • Hub-based networks

  • Bridge-based networks

  • Small switch-based networks

  • Medium and large switch-based networks

  • VLANs

Before examining the case studies of this chapter, consider the following rules of thumb regarding switch design:

  • When designing a network, you should follow some basic steps, such as assessing the network's existing (if any) network, notational and technical drawings, test plans, and implementation plans.

  • Remember that switches break up collision domains, whereas routers break up broadcast domains.

  • When implementing Ethernet, there is a design rule called the "5-4-3 rule" for the number of repeaters and segments on shared-access Ethernet backbones in a tree topology. The 5-4-3 rule divides the network into two types of physical segments: populated (user) segments and unpopulated (link) segments. User segments have users' systems connected to them, and link segments connect network repeaters together. The rule mandates that between any two nodes on the network, there can be only a maximum of five segments, connected through four repeaters (hubs), and only three of the five segments can contain user connections.

By this point in the book, you might be asking yourself, "How have other people handled the issues raised in this book?" Because there is no "one size fits all" for network architecture, this chapter presents some scenarios you might come across in your networking adventures.