Information related to IPv6 support on the Wireless LAN Controller (WLC). Prior to WLC 6.0 release, IPv6 pass-thru is only supported but no L2 security can be enabled on IPv6 WLAN. With WLC 6.0 release and later, IPv6 pass-thru with Layer-2 security supported.
Same Wireless LAN (WLAN) can support both IPv4 and IPv6 clients. IPv6 pass-thru and IPv4 Web auth is also supported on same WLAN. IPv6 is not supported with guest mobility anchor tunneling.
Since controller is a L2 device, no IPv4 or IPv6 routing is supported on WLC controller. that is the reason wireless LAN controller support only bridging mode.
Below is the configuration guide which references IPv6 support.
Currently, the 4400 and 4100 series controllers only support IPv6 client pass-through.
Native IPv6 support is not supported. In order to enable IPv6 on the WLC, check the IPv6 Enable check box on the WLAN SSID configuration under the WLAN> Edit page.
Also, Ethernet Multicast Mode (EMM) is required to support IPv6. If you disable EMM, client devices that use IPv6 lose connectivity. In order to enable EMM, go to the Controller > General page and from the Ethernet Multicast Mode drop down menu, choose Unicast or Multicast.This enables multicast either in Unicast mode or Multicast mode. When multicast is enabled as multicast unicast, packets are replicated for each AP. This can be processor intensive, so use it with caution. Multicast enabled as multicast uses the user assigned multicast address to do a more traditional multicast out to the access points (APs).
Also, there is Cisco bug ID CSCsg78176 (IPv6 pass through is broken with interface assignment and AAA Override), which prevents using IPv6 pass-through when the AAA Override feature is used.
IPv6 Support on WLC and LAP for Release 22.214.171.124
IPv6/Dual Stack Client Support
This section describes new features that have been introduced as part of the IPv6 feature enhancements.
IPv6 Client Mobility
'Intelligent IPv6 Packet Processing enables seamless layer 2 and layer 3 roaming support for both dual stack and IPv6 only client. This feature enables reliable connectivity while roaming.
Cisco 2500 Series Controller requires Multicast-Multicast mode to be enabled with a valid Multicast IP address for IPv6 Client Support.
First-hop security features, including RA Guard automatically blocks rogue router announcements from the controller and access point. Source guard, DHCPv6 Server guard, and IPv6 Access Control List are supported in controller. This feature enables increased network availability and lower operational costs by proactively blocking known threats.
IPv6 Client Management
IPv6 addresses visibility on a per client basis, system-wide IP version distribution, and trends from NCS. This feature enables network administrators to perform IPv6 troubleshooting, address planning, client traceability, and so on from a common wired and wireless management system.
IPv6 Packet Optimization
Intelligent packet processing through NDP proxy and rate limiting of chatty IPv6 packets. This feature enables increased radio efficiency and reduces CPU utilization in the router.
Video for Initial Configuration of Wireless LAN Controller (WLC) using CLI and GUI