Configuring the WLAN

A WLAN consists of Wireless Access Points as discussed in Chapter 2, Networks for Digital Enterprises. These access points (APs) provide the layer 1 and layer 2 functionality of the OSI stack. An AP is a self-sufficient layer 2 device that provides connectivity back to the network. The upstream connectivity from the AP is generally through an Ethernet port on the AP. Sometimes, the APs are used in a mesh mode or as repeaters and the uplink connectivity might also be through a wireless medium. We will consider the APs connected directly to a switch port, which is the most common form of enterprise deployment in this book.

All 802.11 WLANs use a service set identifier, abbreviated as SSID, which is a unique identifier that the wireless clients use to identify and join networks. APs can broadcast this SSID so that it is visible to other users. Some SSIDs might also be hidden and not broadcast, and such networks can be joined by the clients only if they have prior knowledge...