AP Management

[vezeh]

Hi everyone,

I have been experiencing a challenge that I really have not been able to figure out.

I use a CT5520 WLAN controller with code version 8.10.150.

At intervals, I realize that some of my APs just start downloading the software image from the controller even after being associated with the controller for a period of time even though the controller IP is statically configured on the AP. This issue happens repeatedly and I have not gotten a solution to it yet.

Checking capwap events on an AP with this issue, I see the below message;

*Dec 11 13:05:11.927: %CAPWAP-3-EVENTLOG: Echo Request sent to <controller-ip>
*Dec 11 13:05:12.075: %CAPWAP-3-EVENTLOG: Resetting reTransmissionCnt to 0
*Dec 11 13:05:12.075: %CAPWAP-3-EVENTLOG: Queue Empty.
*Dec 11 13:05:12.075: %CAPWAP-3-EVENTLOG: Echo Response from <controller-ip>
*Dec 11 13:05:14.179: %CAPWAP-3-EVENTLOG: Duplicate sequence number 6 in request.
*Dec 11 13:05:17.795: %CAPWAP-3-EVENTLOG: Duplicate sequence number 10 in request.
*Dec 11 13:05:25.843: %CAPWAP-3-EVENTLOG: Duplicate sequence number 32 in request.
*Dec 11 13:05:30.659: %CAPWAP-3-EVENTLOG: Duplicate sequence number 43 in request.
*Dec 11 13:05:34.275: %CAPWAP-3-EVENTLOG: Duplicate sequence number 47 in request.
*Dec 11 13:05:38.483: %CAPWAP-3-EVENTLOG: Duplicate sequence number 55 in request.
*Dec 11 13:05:41.491: %CAPWAP-3-EVENTLOG: Duplicate sequence number 55 in request.
*Dec 11 13:05:41.927: %CAPWAP-3-EVENTLOG: Echo Interval Expired.
*Dec 11 13:05:41.927: %CAPWAP-3-EVENTLOG: Sending packet to AC

I would really appreciate assistance in resolving this issue permanently.

[marce1000]

 - Make sure the involved Intranet-networking between the AP's  and the controller is stable and functional. Preferable use syslog tp remote syslog server for all switches-in-the-path so you have a central point for diagnostic analysis of networking issues, if any.

 M.

[Scott Fella]

So the issue is that you see AP’s in downloading state? If there are specific AP’s that do this, what model AP’s and did you try to delete the image from flash and allow the ap to download the image from the controller again? Seems to me if you see an ap bounce and it’s downloading the code again, it’s an issue with the image. You might have to upload the firmware again to the controller and or delete the image from the AP’s flash.
I ran into this issue once on 8.5 code and it was only happening to one pair of controllers out of a bunch. Downgrading the image didn’t help, uploading the same image didn’t help, but what was weird was I uploaded a newer image and everything was stable and then downgraded to the code I wanted and everything was fine. I worked with TAC and they were surprised also. So try a few things and see if you can get them stable. I’m assuming you have enough licenses and that the AP’s are supported on that code?

[patoberli]

Check this bug:
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvq22269
Which models of APs do you use.

[TsvetanVladimirov81607]

Hey Vezeh,

Do you have other WLCs in your locations that the APs might be going to?

If the AP drops from this WLC and goes to the other, it will grab the version from the other WLC.
Sometimes when the AP goes to another WLC and reboot after downloading its version, it gets back to the first WLC and starts downloading the image again. See if this is not the case.
Check the Uptime. The AP moving between WLCs with the same software version doesn't reload, so if the uptime is long, then this is not the case.

Hope this helps.