CCNA® Cisco Certified Network Associate: Study Guide, Seventh Edition

Internetworking Basics

Before we explore internetworking models and the specifications of the OSI reference model, you’ve got to understand the big picture and learn the answer to the key question: Why is it so important to learn Cisco internetworking?

Networks and networking have grown exponentially over the last 20 years—understandably so. They’ve had to evolve at light speed just to keep up with huge increases in basic mission-critical user needs such as sharing data and printers as well as more advanced demands such as videoconferencing. Unless everyone who needs to share network resources is located in the same office area (an increasingly uncommon situation), the challenge is to connect the sometimes many relevant networks together so all ...