High Cpu on 3750 12S-S

[mortezasadeghi]

Hello
Recently, on one of our switches, the amount of CPU consumption has increased to 90%.
After executing the command show process CPU sorted, I realized that Process RARP had allocated 60% to itself.
Can anyone guide me on what this process is and how I can solve my problem?

CPU utilization for five seconds: 78%/27%; one minute: 66%; five minutes: 65%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
243 268603081 262452919 1023 23.64% 23.83% 24.48% 0 RARP Input

[Leo Laohoo]

Post the complete output to the following commands: 

sh version
sh proc cpu sort | ex 0.00

[balaji.bandi]

Thank you for the input can you also post-show run full configuration to verify.

is this issue recently developed?  Do you know any changes in the config or network.

what kind of traffic is the switch handling?

the post also below output. ( you can upgrade to (12.2.55-SE13) - but let's look at some more information.

show run
show process cpu history
show interfaces switching
show interfaces stat
show log

[mortezasadeghi]

Here you are.

[balaji.bandi]

Can you post-"show run" output also what configured to know cause of this issue.

[Leo Laohoo]

I have never seen a high CPU caused by "RARP input".  

Is Dynamic ARP Inspection enabled?

[mortezasadeghi]

no, just it does inter-VLAN routing.

[Leo Laohoo]

Please post the complete output to the command "sh interface".

[mortezasadeghi]

here you are.

[Leo Laohoo]

Whatever is on Gi 1/0/11 and Gi 1/0/12 is "weird" -- One way traffic.  

[mortezasadeghi]

They connected to a new device but not yet configured.

[marce1000]

 FYI : https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750/software/troubleshooting/cpu_util.html

 M.

[balaji.bandi]

Looks like time for an upgrade if you are running still old IOS (not that you get most updated - since the product is old) - if this device Long uptime try to reboot and check.

also agree on Leo suggestion to post the output to get more clarity of the issue.

[mortezasadeghi]

Hi Balaji.bandi

As I said, the device has been working for a long time, this has just happened, after the reboot, the problem was not solved, even I disabled proxy-arp, but it still did not have an effect on reducing the CPU load.