802.11r BSS Fast Transition on FlexConnect Deployment
In a FlexConnect Deployment scenario, 802.11r BSS FT roaming is supported between APs within the same FlexConnect group. To enable seamless roaming, the 802.11r Key Cache is distributed to all the APs in the same FlexConnect Group. The Key Cache distribution is done by the Cisco WLC after the client device does the initial FT association through Central Authentication.
The Flex deployment supports both Over-the-Air and Over-the-DS roaming. Both the roaming scenarios are illustrated below:
Optimizations for FlexConnect Deployment
The 802.11r Fast Transition (FT) feature for FlexConnect mode APs is optimized such that the FT authentication request process and validation occur at Cisco AP itself and the Cisco AP itself sends FT authentication response. There is no change in the key derivation system.