AP 2702I Reporting High CPU Utilization

[Najib Akbari]

Hi,

I have 10X 2702I APs reporting high CPU utilization while other AP models are fine. the WLC is C9800 17.12.6a

Please assist

[mloraditch]

I can't speak specifically to the problem but the release you are on is deferred, so I would strongly suggest an update. See here: https://www.cisco.com/c/en/us/support/docs/field-notices/743/fn74383.html

Regarding your specific problem, can you give us more detail? Does a reboot resolve the issue? If so for how long? Outside of the actual different models themselves do you have any config that is specific to your 2702s? What type of SSIDs are you serving from them? When did this start? Were there any config changes before the problem appeared? 

This kind of info will help us assist you. 

[Najib Akbari]

I will upgrade the code eventually. can't go beyond 17.12.7a for AP support. here is my answers:
- reloaded the APs and stable for the past three hrs. not sure if going to stay that way or not

- the issue started around a month ago, around the time i applied this patch universalk9_wlc.17.12.06a.CSCws97375.SPA.apsp.bin which perhaps the reason

- no specific config for these APs and SSIDs are similar to other stable APs with different model

[Rich R]

@Najib Akbari although the code is deferred due to FN74383 the cnssdaemon.log bug does not apply to these APs running IOS so I wouldn't be too concerned about that specifically in this context.  APSP4 (which you have installed) has the 2 main bug fixes (CSCwf37271 and CSCwf25731) for that in it anyway.

APSP4 (CSCws97375) only introduces bug fixes for APs running AP-COS (not IOS) so should not affect IOS APs in any way but because they're End of Support now, Cisco no longer tests them at all with new code versions, so if there was an unintended regression it would not have been detected (and realistically might not have been even if they had been tested) so this is the risk you run with using end of life hardware.

As you've confirmed a reboot will usually resolve this kind of issue (at least temporarily) and you can follow the advice already provided to reduce the risk of it happening again but ultimately you will need to look at upgrading to hardware which is still supported because apart from anything else this prevents you from moving to latest IOS-XE versions.

The AP logs (show log) and standard IOS high CPU troubleshooting might give you some clue as to the specific cause of the high CPU.
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750/software/troubleshooting/cpu_util.html

[Stefan Mihajlov]

@Najib Akbari maybe Cleanir, RRM, WMM/QoS causing high CPU, try disable CleanAir on 2.4ghz, check cpu-usage on AP console 🙂
+ move this APs to dedicated site tag/rf profile with reduced features..

[Najib Akbari]

Thank you. its been stable since i rebooted the APs. Im monitoring them and will apply your suggestion if it happen again.

[Stefan Mihajlov]

@Najib Akbari 

If happing again.. do sh tech support and send me:)

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