We have seen problems with other access points and iPhones not roaming properly when a network has IPv6. And we are seeing much the same on Arbuba (IAP-305), so it is likely to be an iPhone bug.
However, I would be interested to hear if others have the same problem, and if Aruba can shed any light on it, and maybe even come up with a work around.
It appears to be specific to 802.11r roaming. Having 802.11k and 802.11v without 802.11r are no problem. It also appears to be an issue when there is IPv6 on the network.
The symtoms are that sometimes (not always) the iPhone messes up the roam between APs, and thinks it has good signal and is connected. However no traffic flows at all (IPv4 or IPv6). You have to turn wifi off and on, on the phone, to clear it. Disabling 802.11r seems to completely fix this, but obviously stops the fast handover.
Any thoughts.