IPv6 support on Wireless Access Point (AP) and Wireless LAN Controller (WLC)

Vinay Sharma · ‎03-14-2011

Introduction

IPv6 support on Wireless AP and controllers

Procedure

Ipv6 is currently not support on any of the Cisco AP's in autonomous mode. However, they will be able to pass ipv6 traffic. This feature is on the roadmap to be implemented in future, however, it not yet clear as to when it will be added.

Regarding ipv6 support on controllers, ipv6 is not supported on 2100 Series Controllers. However, 4400 Series WLC's and Lightweight AP's support ipv6 in a pass through mode. Pass through mode means that even though there will be no actual implementation of ipv6 on the controller, the WLC will be able to bridge the ipv6 packets from one connected device to the other.

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, IPv6 pass-thru with Layer-2 security supported. Same WLAN can support both IPv4 and IPv6 clients. IPv6 pass-thru and IPv4 Webauth is also supported on same WLAN.

IPv6 is not supported with guest mobility anchor tunneling

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 multicast uses the user assigned multicast address to do a more traditional multicast out to the access points (APs).

WLC release 6.0 onwards

Same WLAN can support both IPv4 and IPv6 clients.
IPv6 pass-thru and IPv4 Webauth is also supported on same WLAN.
IPv6 is not supported with guest mobility anchor tunneling.

New Release 7.6.110.0 support

From release Notes for Cisco Wireless LAN Controllers and Lightweight Access Points for Release 7.6.110.0, PMIPv6 Feature is Not Supported on Cisco 2500 Series WLCs
IPv6/Dual Stack client visibility and PMIPv6 feature is Not Supported on Cisco Flex 7500 WLCs but IPv6 client bridging and Router Advertisement Guard are supported.
IPv6 PMIPv6 Feature is Not Supported on Cisco Virtual WLCs

Open Caveats

CSCuh16842
Symptom : Client gets IPv6 address from a different VLAN.
Conditions : This is a combination of the following factors:
Interface group
Client sends traffic from either a static IP address or a previously allocated IP address.
Client traffic does not match the assigned VLAN that was initially received.
The following system message is displayed when this occurs:
Overriding interface of client from 'vlan20' to 'vlan30' within interface group 'vlan20-30'
Workaround : Use DHCP Required.

CSCuc72713
Symptom : Static IP on clients working with interface group VLAN select feature gets assigned to an incorrect interface.
Conditions : Though the static IP subnet exists as a valid interface, it does not get overridden to the correct subnet interface and gets marked into mac-hash interface and the client is unable to pass traffic.
Workaround : Enter the config ipv6 disable command.

Common Questions

Q. What is the auto-anchor mobility feature in Unified Wireless Networks?
A. Auto-anchor mobility (or guest WLAN mobility) is used to improve load balancing and security for roaming clients on your wireless LANs (WLANs). Under normal roaming conditions, client devices join a WLAN and are anchored to the first controller that they contact. If a client roams to a different subnet, the controller to which the client roams sets up a foreign session for the client with the anchor controller. With the use of the auto-anchor mobility feature, you can specify a controller or set of controllers as the anchor points for clients on a WLAN.
Note: Mobility anchor must not be configured for Layer 3 mobility. The mobility anchor is used only for guest tunneling.

Q. Is IPv6 supported on the Cisco Wireless LAN Controllers (WLCs) and Lightweight Access Points (LAPs)?
A. Currently, the 4400 and 4100 series controllers only support IPv6 client passthrough. 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 multicast uses the user assigned multicast address to do a more traditional multicast out to the access points (APs).
Note: IPv6 is not supported on the 2006 controllers.
Also, there is Cisco bug ID CSCsg78176, which prevents using IPv6 passthrough when the AAA Overrride feature is used.