Forum

I'll give it a shot:

PMK Caching = The 802.1x authentication can be skipped on an AP that the client has already autheticated to. Only the 4 way handshake needs to happen. This is useful for a client that needs to reconnect to an AP that it "left" due to signal loss etc.

Opportunistic PMK Caching = A client device can skip the 802.1x authentication and only needs to perform the 4 way handshake when roaming to AP's that are centrally managed by the same "domain" (Trapeze speak), switch, controller etc. Meaning the client doesn't need to authenticate with any specific AP that it wants to roam to as the PMK identifier has been cached at a central location, like the wireless switch.

I think that makes sense anyway...

Brett