Summary

In this chapter, we learned how Layer 2 can be compromised if left unattended, and how VLAN and trunking work. We also saw the different modes of trunking. We then covered the VLAN trunking protocol and how it operates. We also covered Cisco Discovery Protocol and how it can be used in a secure manner.

In the next chapter, we will learn about the security implementation of Layer 2 infrastructure.