WLC loses APs and connection to Mobility Group

Unanswered Question
Oct 6th, 2008
User Badges:

Hi Everyone,

One of our WLCs, a 4402 running, seems to have problems talking to the LAN via it's AP manager ports, it keeps losing contact with it's mobility peers and APs. I've tried replacing the GE SFP, trying port 2 and moving it to another switch port but it only works for a short period before it all goes awry again. I've also reinstalled the image and I was just about to upgrade the controller to when I thought I should ask here for any tips.

Many Thanks


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
jeff.kish Mon, 10/06/2008 - 05:30
User Badges:
  • Silver, 250 points or more

Upgrading the image tends to be a good idea.

Try pinging your AP manager interface. You should NOT be able to ping it - it is unpingable by design. If you get a response, you have a duplicate IP address out there. I've had this situation before, and it results in sporadic AP behavior.

If this doesn't work, please feel free to post some more details about what's going on and maybe me or someone else can help more.

scottwilliamson Mon, 10/06/2008 - 05:43
User Badges:

Hi Jeff,

No, I don't seem to have a duplicate address on the AP manager.

I have taken a look at the stats on the ports and the transmit traffic seems to stop while the problems are occuring. I fear there is something quite wrong with this controller.

I'll try upgrading and see how it goes.



scottwilliamson Mon, 10/06/2008 - 07:12
User Badges:


I'm afraid the s/w upgrade did not make any difference.

any other ideas or suggestions would be gratefully recieved.



rmcgowen Thu, 10/16/2008 - 05:06
User Badges:

I have 6 WLC deployed. I simply made the ap-managment interface one IP address away from the management interface and vlan-tagged both (with the same vlan of course). Then the two switch ports they connect to are trunked. I can ping the management interface and not the ap-management as expected. Not problems with this design.

Then all the other virtual interfaces are tagged and can communicate out the managment interface to the LAN. My understanding is the the ap-manangement is only for WCL - AP communications.

Here is an example of the switch port the WLC's manangment port connects to:

interface GigabitEthernet6/25

description SAR260WLC1

switchport trunk encapsulation dot1q

switchport mode trunk

and the ap-management is the same.

Hope this helps.

Scott Fella Thu, 10/16/2008 - 18:28
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    The Hall of Fame designation is a lifetime achievement award based on significant overall achievements in the community. 

  • Cisco Designated VIP,

    2017 Wireless

Does the ap join another ap and do you see the ap's trying to join the primary again. What to look for is the time the ap has been associated to the ap. You can find this info on the wireless tab and by clicking on one of the ap's. If you put a sniffer on the network and sniff the management vlan, see if you see any response from the wlc. If not then either you wlc went bad or you do have a duplicate IP address as Jeff mentioned.

scottwilliamson Wed, 10/22/2008 - 05:32
User Badges:

Hi Everyone,

Thanks for your suggestions, our maintainer supplied a replacement WLC, which I configured and it's all back up and running.




This Discussion



Trending Topics - Security & Network