Slaac has stopped working on WLC 8510

[netops2014]

Hi,

We have two cisco 8510 WLCs (Active/Standby Hot) in our network.

Each one is connected directly into a Core (6509) and all had been running fine until we upgraded the Software

We upgraded  from code 7.6.130 to 8.0.133.

All interfaces are set up on the WLC with IPV4 addresses but they had been able to get an IPV6 address via Slaac from our Core.

Clients now still get an IPV4 address but cannot obtain an IPV6 address.

We have tested slaac by plugging a laptop directly into one of the VLANs on our core. We get both an IPV4 and IPV6 address, so slaac is still working.

The Software on our core and the WLAN/SSID properties have not changed at all.

From doing a wireshark on a client i can see that it is not getting any ICMPv6 traffic nor any RAs from the Core.

Does anyone know of anything that could be stopping this. RA Guard is enabled on the WLC and on the APs but i believe it was before the upgrade.

Thanks

Net Ops

[wwbishop2]

Ever get a resolution to this issue? We're seeing the same behavior on an 8510 HA pair running 8.2.161.

[netops2014]

Hi,

No, we did not find a solution for this yet. We are due to upgrade the software and i am hoping this may fix it. Did not at the time find any more information on it. Did you have any luck?

Thanks

[wwbishop2]

We moved to stateful DHCPv6 with no luck, but based on some packet inspection found that RAs were not being passed through to clients (no default gateway received). Enabling RA throttle policy on the WLCs fixed our issue, though we have not tested this yet using SLAAC. My suspicion is it will work as well. 

One the throttle policy was enabled, RAs started flowing. Hope this helps. 

[netops2014]

Hi,

Thanks for the reply. I managed to do a wireshark on it and yes, I could see our clients not getting RAs. I enabled the RA throttle policy and it is now working, using SLAAC. We never historically had this setting on, so i never suspected it needed to be. Thanks a million for your help!