An engineer must ensure that the wireless network can accomplish fast secure roaming by way of caching keys on the access points. Which key caching mechanism is enabled by default on a Cisco AireOS…

SKC (Session Key Caching) is a client-side mechanism where the client itself retains cached keys, not a controller-side AP distribution mechanism, and it is not the default on AireOS.

OKC (Opportunistic Key Caching) allows the WLC to proactively push the client's Pairwise Master Key Security Association (PMKSA) to all APs in its mobility domain; when the client roams, the target AP already holds the cached PMK and the client can complete a two-way handshake instead of a full EAP exchange, achieving fast secure roaming without any special client support requirement.

802.11r (Fast BSS Transition) is an industry-standard protocol that requires explicit configuration on the WLC and matching support on the client device - it is not enabled by default.

CCKM (Cisco Centralized Key Management) is a proprietary Cisco protocol that requires Cisco Compatible Extensions (CCX) on the wireless client and is not the default key caching method on AireOS WLCs.