Chapter 2. Switching Design

This chapter discusses switching network design and includes the following sections:

• Making the Business Case

• Switching Types

• Spanning Tree Protocol

• Virtual LANs

• Multilayer Switching and Cisco Express Forwarding

• Switching Security

• Switching Design Considerations

This first chapter in Part II, "Technologies: What You Need to Know and Why You Need to Know It," discusses switching network design. After introducing why switches are an important part of a network, we examine the different types of switching and then discuss the Spanning Tree Protocol (STP), which is key in Layer 2 switched environments to ensure that redundancy does not cause the network performance to deteriorate. Virtual local-area networks (VLANs) are then described. Two types of Layer 3 switching, multilayer switching (MLS) and Cisco Express Forwarding (CEF), are then introduced. Security in a switched environment is examined next. The chapter concludes with considerations and examples of switched designs.

Note

Appendix B, "Network Fundamentals," includes material that we assume you understand before reading the rest of the book. Thus, you are encouraged to review any of the material in Appendix B that you are not familiar with before reading the rest of this chapter.