After selecting the SSID, the wireless client makes its DHCP discovery, this arrives at the DHCP relay (switch) and is sent as unicast to the DHCP server. The dhcp server then sends out his DHCP offer and then it starts again.
The offer arrives at the switch as a reply and will continue to send in the direction of HWC. Unfortunately, it does not arrive at the wireless client (checked with wireshark).
The testlab is based on the Extreme wireless Controller 10.51.04.0009 (VMWare VM V2110). The admin interface is untagged and teh interfaces esa0 and esa1 are tagged. esa0 is used for AP registration (topology interface physical) and esa1 is used for clients. The client topology is bridged@controller.