Chapter 11

Switching and Virtual LANs

The Following CompTIA Network+ Exam Objectives Are Covered in This Chapter:

• 1.4 Explain the purpose and properties of routing and switching.
  • Spanning Tree Protocol
  • VLAN (802.1q)
  • Port mirroring
• 2.1 Given a scenario, install and configure routers and switches.
  • VLAN (trunking)
  • Interface configurations
• MAC filtering
• PoE
• VTP configuration
• QoS
• Port mirroring

Layer 2 switching is the process of using the hardware addresses of devices on a LAN to segment a network. Because you’ve got the basic ideas down, I’m now going to focus on the more in-depth particulars of Layer 2 switching and how it works.

You already know that switching breaks up large collision domains into smaller ones and that a collision domain is a network segment with two or more devices sharing the same bandwidth. A hub network is a typical example of this type of technology. But because each port on a switch is actually its own collision domain, you can create a much better Ethernet LAN network by simply replacing your hubs with switches!