Chapter 9. Switching Security

What You Will Learn

On completing this chapter, you will be able to:

  • Describe switch-based security features

  • Explain how networks are attacked in a switched LAN environment

There is an English proverb that states, "It is an equal failing to trust everybody, and to trust nobody," and it is the goal of network security to avoid both these failings. Network security is similar to putting your guard dog, Patches, to work for you guarding your network against any and all threats, as illustrated in Figure 9-1. This chapter focuses on establishing security for virtual local-area networks (VLANs). And as you recall from Chapter 8, "Virtual LANs (VLANs)," VLANs are a logical grouping of devices that might or might not be physically located close to each other.

Figure 9-1. Patches Guarding the Network


Just as Patches can be bought off with a steak, however, intruders can find ways into your network that you never imagined. It is best to be vigilant and protect your network and its resources as you would protect your own children.