Disconnects and slow speeds: find rx fifo "overflows" in the logs

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Hi Community,

Today I had some coplaints about disconnects and slow speed.. I See in the logs some warnings like below:

Hundreds of this:

[wifi]: wl1: 1 rx fifo 0 overflows!
[wifi]: wl1: 1 rx fifo 0 overflows!
[wifi]: wl1: 1 rx fifo 0 overflows!
[wifi]: wl1: 1 rx fifo 0 overflows!
[wifi]: wl1: 1 rx fifo 0 overflows!
[wifi]: wl1: 1 rx fifo 0 overflows!

And a few hundred like this: 

2018-03-26 09:34:27 info    ah_auth: Recieve sync reply for station(6003:08a9:fe32) from (10.60.2.220) buf-size (1296) time sec(1522049667) usec(436724) len (1312)
2018-03-26 09:34:27 info    ah_auth: Recieve sync reply for station(6003:08a9:fe32) from (10.60.2.220) buf-size (1296) time sec(1522049667) usec(435286) len (1312)
2018-03-26 09:34:27 info    ah_auth: Recieve sync reply for station(6003:08a9:fe32) from (10.60.2.220) buf-size (1296) time sec(1522049667) usec(433842) len (1312)
2018-03-26 09:34:27 info    ah_auth: Recieve sync reply for station(6003:08a9:fe32) from (10.60.2.220) buf-size (1296) time sec(1522049667) usec(432398) len (1312)
2018-03-26 09:34:27 info    ah_auth: Recieve sync reply for station(6003:08a9:fe32) from (10.60.2.220) buf-size (1296) time sec(1522049667) usec(430949) len (1312)
2018-03-26 09:34:27 info    ah_auth: Recieve sync reply for station(6003:08a9:fe32) from (10.60.2.220) buf-size (1296) time sec(1522049667) usec(429410) len (1312)

show cpu detail shows this:

CPU total utilization:                56.650%
CPU user utilization:                 43.842%
CPU system utilization:               1.477%
Number of interrupt in last second:   889
Interrupt utilization:                0.000%
Soft interrupt utilization:           11.330%

What does this mean, and what can we do for it.. 

Thanks in Advance.. 

Kind regards, Joy,
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joy

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Posted 3 months ago

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joy

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Hello, I have realized that the CPU user utilization is too hight.. What could be the reason of this? 

AH-e8c200#show cpu detail
CPU total utilization:                53.465%
CPU user utilization:                 48.514%
CPU system utilization:               0.990%
Number of interrupt in last second:   292
Interrupt utilization:                0.000%
Soft interrupt utilization:           3.960%
------------------------------------------------------------
CPU0 utilization:
CPU total utilization:                8.910%
CPU user utilization:                 3.960%
CPU system utilization:               1.980%
Interrupt utilization:                0.000%
Soft interrupt utilization:           2.970%
------------------------------------------------------------
CPU1 utilization:
CPU total utilization:                97.029%   <----------
CPU user utilization:                 93.069%   <---------
CPU system utilization:               0.000%
Interrupt utilization:                0.000%
Soft interrupt utilization:           3.960%


Thanks,

Joy
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Gary Smith, Official Rep

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Hi Joy,

When looking at High CPU, it is interesting to look at the output of "show system processes state". This will list the processes running on the AP and their CPU consumption. It may tell you which process is using the CPU resource. It looks like you have already isolated this to l7d. Without seeing more data, it's difficult to help. Have you opened a support ticket?

Kind Regards,
Gary Smith
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Dennis Wright

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Joy,

We just had a similar problem after upgrading to 8.2 firmware on our 130's and 230's.  We rolled back to 6.5 and solved most of the issues.  We also think there was some PC driver problems that exacerbated the firmware issues.

Dennis

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joy

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Hi Dennis, 

I was going to install the 8.2 as well, because I'm running the 6.5r8 now.. but it seems that 8.2 doesn't provide a solution then. 

I saw also CPU peaks on that AP, and specifically the l7d process which is being used for application visibility.. Is 

I tried some commands like: 
"application identification shutdown" and "application reporting disable"
-->but still saw /opt/ah/bin/l7d running

Then tried "exec avc reset" (should reset this proces, found here in community post), but still saw l7d process using top CPU .. I just rebooted the AP now, and see the process not using much CPU anymore.. 


Is it possible to disable application visibility on a specific AP? and what are the possible impacts?

Thanks,

Joy,