High cpu utilization in 4507R-E

[yadavsandip]

Hi, it is 4507R-E having ios: cat4500e-ipbasek9-mz.150-2.SG.bin; previously its cpu utilization was 0 to 1%; suddenly it reached up to 58%; after searching i found its ios bug so upgraded ios to above mentioned one. after that still it shows 45%. I always find "Cat4k Mgmt LoPri" process which uses high process.

Core_4507_A#sh processes cpu

CPU utilization for five seconds: 45%/2%; one minute: 34%; five minutes: 34%

PID Runtime(ms)   Invoked      uSecs   5Sec     1Min     5Min   TTY  Process

    7     2346546     221800       10579   0.79%  0.19%  0.12%   0  Check heaps

    14     4596022  15525901      296     2.23%  0.39%  0.30%   0  ARP Input

    56    65232074 285296494     228     7.75%  5.36%  4.65%   0  Cat4k Mgmt HiPri

    57   1869145191146026151    163     23.03%19.91% 20.35% 0  Cat4k Mgmt LoPri

    176    64055490  12360083     5182   4.63%  4.48%  4.47%   0 CEF: IPv4 proces

i am not finding any other issue; is it really actual traffic is increased or is there any issue? how would i conclude! Pl guide me....

[sdheer]

Hi Sandeep ,

The baseline CPU utilisation for 4500 switches is  around 40 % , so you do not need to worry about 45 % cpu.

You can check teh same in the below doc:

http://www.cisco.com/en/US/products/hw/switches/ps663/products_tech_note09186a00804cef15.shtml

Regards,

Swati

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[yadavsandip]

Hi Swati, Thanx for ur response...in above doc, there is sentence like

"Five-second CPU utilization is expressed as:x%/y%

The x% represents total CPU utilization, and y% represents the CPU that is spent at the interrupt level. When you troubleshoot Catalyst 4500 switches, focus only on the total CPU utilization."

What is meant by y% in the sense wt is meant by highlighted sentence;which is 2% in this case.

[Derek Zhang]

you can use the documentation above for troubleshooting e.g. show platform cpu packet statistics, show platform health.

You'll have more clue for which process/queue utilize the Hi/Low Mgmt.

Hi/Low are very general process on Cat4K. normally relates to l2 STP/Mac learning. flood of traffic, mac flapping, network loop may also causes the 2 processes high cpu.