LAN Switching and Wireless CCNA Exploration Companion Guide Wayne Lewis, Ph.D. LAN Switching and Wireless, CCNA Exploration Companion Guide is the official supplemental textbook for the LAN Switching and Wireless course in the Cisco Networking Academy CCNA® Exploration curriculum version 4. This course provides a comprehensive approach to learning the technologies and protocols needed to design and implement a converged switched network. The Companion Guide, written and edited by a Networking Academy instructor, is designed as a portable desk reference to use anytime, anywhere. The book’s features reinforce the material in the course to help you focus on important concepts and organize your study time for exams.