catalyst 3750 high cpu (spanning-tree) even after disabling spanning tree

[Nicolas Maton]

Hi,

I'm looking for an explenation.

I have disabled spanning-tree on my stacked catalyst 3750's. 

switch#sh spanning-tree

No spanning tree instance exists.

However the spanning tree process still remains at 30+%.. some moments the switch goes to 80%+

switch#show processes cpu sorted | exc 0.00

CPU utilization for five seconds: 51%/4%; one minute: 53%; five minutes: 58%

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

 220  26998131352225719811          0 32.53% 32.19% 32.58%   0 Spanning Tree    

   9  18731538913567807945          0  3.66%  3.43%  3.94%   0 ARP Input        

 167  2252711720  65652703      34313  3.50%  3.16%  3.13%   0 PI MATM Aging Pr 

 145   4523379461399674340        323  1.11%  1.13%  1.08%   0 Hulc LED Process 

 106   204130136  98476206       2072  0.47%  0.30%  0.28%   0 hpm counter proc 

  41    90142651  15430079       5842  0.15%  0.15%  0.15%   0 Compute load avg 

  44    27196496  18587099       1463  0.15%  0.04%  0.05%   0 HC Counter Timer 

  35    44370625  66207940        670  0.15%  0.08%  0.06%   0 Per-Second Jobs  

  72    29120406 110630763        263  0.15%  0.03%  0.03%   0 hrpc <- response 

 155   106052423  54633914       1941  0.15%  0.16%  0.15%   0 HRPC qos request 

 200   522703385 549493508        951  0.15%  1.08%  1.04%   0 CDP Protocol     

  81    28065178 108474059        258  0.15%  0.08%  0.07%   0 HRPC hlfm reques 

Anyone has an idea why this is? 

Thanks ! 

[Reza Sharifi]

Hi,

What version of IOS are you running?

[Nicolas Maton]

HI, 

ROM: Bootstrap program is C3750 boot loader

BOOTLDR: C3750 Boot Loader (C3750-HBOOT-M) Version 12.2(44)SE5, RELEASE SOFTWARE (fc1)

Cisco_Switch_DC uptime is 2 years, 9 weeks, 4 days, 16 hours, 51 minutes

System returned to ROM by power-on

System restarted at 21:49:45 CET Tue Nov 20 2012

System image file is "flash:/c3750-ipservicesk9-mz.122-55.SE5.bin"

[Leo Laohoo]

Upgrade to 12.2(55)SE9.  The version you're running is not yet stable.

[danibqb01]

Hello guys,

I'm having this same problem, STP is disabled, but the spanning tree process consumes about 18% of the CPU.

IOS run: version 15.2 (4) E8.

------------------ show running-config ------------------

!
spanning-tree mode rapid-pvst
spanning-tree extend system-id
no spanning-tree vlan 1-4094
!

------------------ show spanning-tree ------------------

No spanning tree instance exists.

Would anyone have any ideas?