Introduction

Virtual local area networks (VLANs) represent the logical separation of physical LANs. A VLAN allows you to split up your 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. Up until now only one group policy has been supported by Cisco s wireless access. Due to this one access point/one policy limitation, any wireless client group not compatible with the main policy settings have to use their own separate compatible access points. With the introduction of VLANs into a wireless network, you can define multiple compatible group policies such as voice and data groups that allow you to use one access point for all of your 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.

WLANs have been widely used in the wired LAN industry since the 1990s.The VLANs proven support of scalability and cost savings are required by network administrators and architects in LAN network deployments.

Cisco has taken VLAN technology from wired LANs and its standards and incorporated it into its wireless devices to offer some of the advantages of a WLAN such as scalability, security, and per-VLAN policy, thus making wireless networks more scalable and appealing to corporations and more cost effective.

This chapter reviews the basic workings of the...