I am working on a WLC deployment where the AP and WLC will be using ipv6 for CAPWAP connectivity. Based on the discovery algorithm the AP should attempt to discover the WLC via a link-local multicast, through dhcp option and then through dns by sending a query to CISCO-CAPWAP-CONTROLLER.xxx.
I am attempting to get the access point to use discovery via dns but the AP will not send a dns query for the dns name if ipv4 is not enabled on the AP. The AP is using Stateless autoconfig to calculate it's global unicast ipv6, is able to pickup the ipv6 dns server (show ipv6 dhcp interface) and I am able to ping the dns name CISCO-CAPWAP-CONTROLLER.xxx from the AP (via console).
Packet capture and debugs on the AP confirms that the AP sends a dns query when it has an ipv4 address but no dns query if it has no ipv4 address and just an ipv6.
The AP model is 1602 on 8.2.151 firmware.
Is this a bug or something that needs to be fixed in a future update?