Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

Table Of Contents
1-85
Introduction
Layer 2 and Layer 3 Roaming Between RPs and Modules
When necessary, tunnel traffic back to a station’s HM—Every
module in the Layer 3 roaming domain establishes a tunnel to every other
module. A module tunnels traffic only when necessary, which is when a
station that has an HM on a different VLAN roams to the module. If a
station that has an HM on the same VLAN roams to the module, the module
simply becomes the station’s new HM. This provisions eliminates
unnecessary and inefficient tunneling.
Wireless Edge Services xl Modules’ Layer 3 roaming capabilities provide
seamless roaming (sessions maintained) between RPs on different modules
regardless of the security options on the WLAN. However, fast roaming at
Layer 3 is not supported except when modules implement a redundancy group
and Web-Auth. For more information about roaming, see Chapter 9: Fast
Layer 2 Roaming and Layer 3 Mobility.