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New Member

High CPU Usage on 3750


I have this 3750 old switch running c3750-ipbase-mz.122-35.SE5.bin (I know it is old...) and it is used for connecting remote offices via 10Mbps circuits. It has been running fine for the last 12-month. But recently, I found the CPU usage is a little bit high, like in screenshot.

I know the average CPU usage is only about 10-20% but it bothers me that it constant has MAX CPU usage around 90+%...I also did show processes cpu sorted and the only thing having 3+% CPU usage is spanning tree...but that won't be enough to cause the CPU peaks... There is no special feature configure on the switch, just VLAN taggings.

Any suggestions on what to check?


  • WAN Routing and Switching
Everyone's tags (2)
Super Bronze

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Your stats don't show a constant max CPU of 90+%, they show spikes of 90+%, happening (it appears) once every 30 minutes.

New Member

"Constant" might sound

"Constant" might sound confusing but every 30-min bothers me really bad as well...

New Member

Hi,Reboot it once and check


Reboot it once and check the status.

New Member

It is hard to schedule an

It is hard to schedule an reboot of that switch but it will be used as the last resort.

New Member

Hi,Please find the EEM script


Please find the EEM script to configure it in the switch. After that please share the output.

event manager session cli username "Privlige 15 leve user"
event manager applet cpuspike
 event snmp oid get-type next entry-op ge entry-val "60" exit-time 20 poll-interval 1
 action 1.0 syslog msg "chinese_ys: high CPU - check nvram:cpuinfo file."
 action 2.0 cli command "enable"
 action 3.0 cli command "show clock | append nvram:cpuinfo"
 action 4.0 cli command "show proc cpu sort | append nvram:cpuinfo"
 action 5.0 cli command "show log | append nvram:cpuinfo"
 action 6.0 cli command "u all"
 action 7.0 cli command "term length 24"


BR// Sanjay

New Member

Thanks, I will try those

Thanks, I will try those later.

But once it is configure, should I also syslog server or just show log will give me the capture?

New Member

Hi,Please configure ur snmp


Please configure ur snmp polling server to poll in an interval of 4 hr or 6 hr.

And  remove all the unnecessary snmp trap. 

To troubleshoot step by step:

1) Remove the snmp config from the switch, now monitor.

2)Hope ur cpu is behaving normal, now configure the snmp and enable the required snmp trap, don't enable all and check the cpu .status.


Please rate if the EEM & tshoot has provided solution.



New Member

I will do this and report

I will do this and report back.

New Member

I pretty much disabled all

I pretty much disabled all the health monitors of switch from SNMP server and output of sh processes cpu history is indeed reduced to MAX @ 80-85% from 95%. But still more than my expected 50-60%.