Summary
Now that you have completed this chapter, you should a have a firm understanding of the following concepts: 
  • Broadcasts are useful and necessary traffic; however, too much broadcast traffic can cause network performance problems. Managing broadcast traffic is a critical aspect of campus LAN design. 
  • The location of common workgroups and servers can have a significant impact on traffic patterns. 
  • Adding additional bandwidth is not the long-term solution to meeting the needs of high-priority traffic. 
  • Multilayer switching combines Layer 2 switching and Layer 3 routing functionality. 
  • The multilayer design model is inherently scalable. Layer 3 switching performance scales because it is distributed. Backbone performance scales as you add more links or more switches. 
  • A switch block is the unit that contains distributed network services and network intelligence. A switch block consists of Layer 2 switches, Layer 3 routers, and, sometimes, distributed servers. 
  • A core block is the unit that transfers cross-campus traffic. It can consist of Layer 2 or Layer 3 devices. 
  • The purpose of network link redundancy is to provide alternate physical pathways through the network in case one pathway fails.