6 Replies Latest reply: Sep 17, 2009 9:51 AM by dmantill RSS

    wireless controller 4400

    Jonathan Vosolo





      had a WLC 4402 wireless controller which I confirgured to register 15 cisco aironet1130 AG series lightweight access point.



      the configuration was successfull, the network has been up for quite some time. but it comes a time when the ap's are not able to register on the controller hence downing the whole wireless network.



      I've got a new ios software which I want to install to replace the software on the controller....my worry is since the ap's are not registered on the controller, If I uprade the controller will the ap's be able to register with this new IOS installed



      please help before I make a mistake



        • 1. Re: wireless controller 4400
          Jamie Sobczyk

          I believe that when you try to register the APs to the controller again, it will upgrade the code on the APs to match.

          • 2. Re: wireless controller 4400
            Dwayne Fields

            Jamie is correct. Just upgrade the WLAN controller and APs will upgrade their code to match.

            These topic of LWAPP access points discovery, join, and code are covered in the scope of CCNA-Wireless topics.

            • 3. Re: wireless controller 4400



              How did the upgrade go after on those AP's ?


              Did you ever find out why the AP's did not registger with the controller ?




              • 4. Re: wireless controller 4400
                Adrian Soh



                Very interesting problem!  May I suggest to upgrade your WLC software to 4.2.176 as a bare minimum.  This is a very good stable version.  If you would better RRM features go 5.2.157 then 5.2.178 (it requires the boot from 5.2.157).


                The issue you outlined sounds like a LWAP JOIN issue.. aka WLC discovery problem.


                I'm uncertain of your architectural design but you can ensure WLC Discovery with the following:

                1. resolving CISCO-LWAPP-CONTROLLER to the mgmt address of your primary WLC as a bare minimum
                2. DHCP option 43 defined on the vlan that the APs reside in.  This option will define IP Address of all the WLCs (recommendation option)
                3. defining all WLCs in same mobility group (and same Virtual Interface address)
                4. and prepare to be amazed...


                Hope this helps


                • 5. Re: wireless controller 4400
                  Adrian Soh

                  Has this issue been resolved? I'm assuming silence is golden....




                  • 6. Re: wireless controller 4400



                    There are a lot of possible reason why this is failing.

                    At first, I will start checking:

                    1) How are the APs been power up?

                         If you are using PoE. Make sure that switch can provide enough power or at least that you are not having any issue or logs related to power.

                    2) Are all the APs connected to the same switch? Are these losing connectivity at all? Could it be the uplink to the WLC? Or could it be a faulty switch?

                    3) If you are using 440x WLC, make sure that if you have LAG (Etherchannel) enabled,  make sure that you have scr-dst-ip as load balance and that Po Interface is setup exactly the same as the physical ones.


                    4) If this behavior is happening on all units at the same time, this could be a WLC issue, you may better check the "show msglog" "show traplog" for new events, maybe realted to this. Another possibility could be that the WLC is crashing, or failing in a process and therefore generating tracebacks.


                    5) APs could be crashings, yo can check that information to on the WLC.


                    6) If APs are not joining back again, it will be a good idea to console the unit and monitor these in order to retrieve more information, another option will be running debugs on both sides in order to understand why this is not joinig to the WLC. You might want to see this link:

                    Troubleshooting APs not joining the WLC.: http://tiny.pl/z6v9




                    Regarding the upgrade, it sounds like a must Go to the latest 4.2 version (, that one is quite stable.

                    Do not worry about how the APs will be upgraded. Once the APs are joining the WLC these will download the IOS from the WLC automatically.

                    Hope it gives you an idea for your own action plan