Chapter 9 - Wireless LAN VLANs

Abstract

The chapter reviews the basic working of virtual local area networks (VLANs) used on wired networks. The chapter discusses specific protocols and functions that make up a VLAN and its technology. A VLAN allows user to split up physical network devices, such as Cisco's switches and access points, into different virtual local area networks (LANs), in which each VLAN takes on its own unique characteristics. With the introduction of VLANs into a wireless network, one can define multiple compatible group policies—such as voice and data groups—that allow user to use one access point for all of unique wireless client groups. VLANs can also be characterized and used to represent a group of devices on different physical LAN segments that can then communicate with each other as if they are on the same physical LAN. Cisco has taken VLAN technology from wired LANs and its standards, and incorporated it into its wireless devices to offer some of the advantages such as scalability, security, and per-VLAN policy of a WLAN, thus making wireless networks more scalable, cost effective, and appealing to corporations.