Appendix A. Answers to Chapter Review Questions
Describe why postal addresses and telephone numbers are routable.
Answer: A postal address has three components that can be used to deliver mail: state, city, and street. A phone number has an area code and exchange. At the core layer, mail can be delivered to the next post office based on only the state or city and state information. A phone number is delivered at the core layer based on the area code.
What is the purpose of a default route?
Answer: A default route is used if there is not a specific entry in the routing table for the destination.
Describe the difference between routing and switching.
Answer: Routing moves a letter or telephone call to the access layer (as ...