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3750 high cpu utilization

Level 1
Level 1


  for some reason my 3750 stack is showing high cpu utilization, we don't have any user on site now but its showing high when there is no users, 

show processes cpu sorted | ex 0.0
CPU utilization for five seconds: 56%/29%; one minute: 74%; five minutes: 84%
 PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process
 146    17498576   5797497       3018 11.16% 10.49% 10.53%   0 Hulc LED Process
   4     3405540    149175      22829  8.29%  1.29%  1.11%   0 Check heaps
 224     1651272   1897447        870  0.47%  0.39%  0.40%   0 Spanning Tree
 165     2275369     86997      26154  0.47%  0.58%  0.58%   0 Power RPS Proces
 156     1291635    421364       3065  0.47%  0.42%  0.44%   0 HRPC qos request
 120         707       192       3682  0.31%  0.44%  0.14%   1 SSH Process
 203      348137    435326        799  0.15%  0.16%  0.10%   0 CDP Protocol


show ver
Cisco IOS Software, C3750 Software (C3750-IPBASEK9-M), Version 12.2(55)SE7, RELEASE SOFTWARE (fc1)

Any help is appreciated, 



3 Replies 3

Reza Sharifi
Hall of Fame
Hall of Fame


It appears that "Hulc LED Process" is eating up about 10.53% of your processor which is not too bad. I have seen it a lot higher.  All the other processes are fine unless there are some more that you did not post.  If the CPU is always running high, you may want to look at other IOS images and upgrade.



InayathUlla Sharieff
Cisco Employee
Cisco Employee

Please find my document below on troubleshooting high cpu on this platform:-


20-30 % of HULC LED process is normal  and expected for these DSBU



this is expected CPU utilization, specific to what CPU does under Hulc LED process, it is

non-impacting and non-intrusive process.

Every 40 ms the "Hulc LED" process does following tasks:


- Check Link status on every port

- If the switch supports POE, it checks to see if there is a Power Device (PD) detected,

this check is bypassed if the switch does not support POE

- Check the status of the transceiver

- Update Fan status

- Set Main LED and ports LEDs

- Update both Power Supplies and RPS

- Check on system temperature status





Hi Sharief 

  How can we fix this Issue, I notice a lot of ports flap. is there any solution to fix, or we should leave it like this.?


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