Symptom

IOS-APs in flexconnect with MTU lower than 1500 are not processing DOT11R_WLC_MAC_IP_PAYLOAD causing 11r clients to fail roaming show capwap reap dot11r shows no R0-KHID value for connected clients. AP is replying with assoc-resp R0-KHID all zeros

Conditions

Observed in 9800 with IOS-APs in flexconnect when MTU is lower than 1500

Workaround

Modify mobility group name to push dot11r payload again to APs, be aware of CSCwf83132

Further Problem Description