Cisco Systems 3.2 manual 10-3, Inter-Controller Roaming

Chapter 10 Configuring Mobility Groups

Overview of Mobility

The process becomes more complicated, however, when a client roams from an access point joined to one controller to an access point joined to a different controller. It also varies based on whether the controllers are operating on the same subnet. Figure 10-2illustrates inter-controller roaming, which occurs when the controllers’ wireless LAN interfaces are on the same IP subnet.

Figure 10-2 Inter-Controller Roaming

When the client associates to an access point joined to a new controller, the new controller exchanges mobility messages with the original controller, and the client database entry is moved to the new controller. New security context and associations are established if necessary, and the client database entry is updated for the new access point. This process remains transparent to the user.

Note All clients configured with 802.1x/Wi-Fi Protected Access (WPA) security complete a full authentication in order to comply with the IEEE standard.

Figure 10-3illustrates inter-subnet roaming, which occurs when the controllers’ wireless LAN interfaces are on different IP subnets.

Cisco Wireless LAN Controller Configuration Guide

OL-8335-02 10-3