03-03-2019 10:55 PM
Hello guys,
Our C3850 switches' CPU high frequent.
#show version
Switch Ports Model SW Version SW Image Mode
------ ----- ----- ---------- ---------- ----
* 1 16 WS-C3850-12XS 16.6.5 CAT3K_CAA-UNIVERSALK9 BUNDLE
2 32 WS-C3850-24S 16.6.5 CAT3K_CAA-UNIVERSALK9 BUNDLE
3 56 WS-C3850-48T 16.6.5 CAT3K_CAA-UNIVERSALK9 BUNDLE
C3850#sho processes cpu sorted
CPU utilization for five seconds: 97%/39%; one minute: 79%; five minutes: 48%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
320 19034620 84249648 225 37.65% 27.86% 9.94% 0 SISF Switcher Th
441 17494771 132071721 132 9.67% 7.32% 3.33% 0 SISF Main Thread
233 107421511 156391654 686 7.92% 7.65% 7.43% 0 Spanning Tree
117 35755203 719432257 49 2.29% 2.25% 1.97% 0 IOSXE-RP Punt Se
35 13504890 53040175 254 1.98% 1.30% 1.21% 0 ARP Input
53 11100011 65588362 169 1.42% 0.93% 0.91% 0 ARP Snoop
209 4940552 27356792 180 0.47% 0.45% 0.53% 0 IP Input
There is a phenomenon that When the log "%PLATFORM_MATM-4-QUEUE_OVERLIMIT: MATM dropped learn cache batch messages as queue limit has reached." show up, The CPU will high suddenly last about few minutes then recover to normal
I saw the process of "SISF Switcher Th " occupy a part of cpu ,and I search a bug CSCvk32439 similar to this
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvk32439/?rfs=iqvred
But the platform is C2960-X not C3850,How can I fix this ?
Thank you for any answers
03-03-2019 11:12 PM
Do you have any recent upgrades done ? what is your QoS configuration.
as per the resolved issue, your version should have resolved as per release document.
03-04-2019 12:10 AM
03-04-2019 12:30 AM
CSCvg26012, CSCvk32439
03-04-2019 12:50 AM
03-04-2019 02:43 AM
06-29-2023 10:35 AM
We're having same issue on a 3850-12XS running 16.12.08 - I attempted disabling dhcp snooping but cpu still hovering 88-99% - we are dropping pings as this thing either can't handle the load or something is buggy in this OS.
CPU utilization for five seconds: 97%/11%; one minute: 90%; five minutes: 89%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
338 1862090940 1467058749 1269 37.60% 33.99% 33.11% 0 SISF Switcher Th
339 1864621743 1405946580 1326 30.25% 33.23% 33.01% 0 SISF Main Thread
06-29-2023 03:52 PM
Post the complete output to the following commands:
sh platform resource
sh platform software status con brief
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