6509-E High CPU - No processes ?

[Rajagopal Sivaramakrishnan]

Hi All

We have a pair of 6509-E with SUP 720 which constantly shows decently high CPU - 60-80 %... We arent sure what is driving this CPU ! Show proc cpu doesnt give any process which is consuming the cpu !  Initially we thought it could be due to RPF filters on each VLAN interface, but it wasnt the case. This switch has all user vlans, and there is an access-list defined on each of these VLAN interfaces.. We were planning to remove this , but wasnt sure if there was anything else that I need to look for ?

DL#show proc cpu sorted

CPU utilization for five seconds: 60%/53%; one minute: 58%; five minutes: 60%

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

273   2832223801442015448        196  2.07%  1.63%  1.50%   0 IP Input

562         240         9      26666  1.59%  0.12%  0.02%   1 SSH Process

493    62073096 284696998        218  0.47%  0.15%  0.14%   0 Port manager per

353    34279688  37585873        912  0.39%  0.52%  0.53%   0 CEF: IPv4 proces

  12    87729364 270528221        324  0.31%  0.54%  0.54%   0 ARP Input

563        2324      1130       2056  0.23%  0.03%  0.05%   2 Virtual Exec

555    17914820 279025216         64  0.15%  0.11%  0.08%   0 HSRP IPv4

404       65952    133601        493  0.15%  0.05%  0.05%   0 TPLUS

  35     1055240  24322173         43  0.07%  0.00%  0.00%   0 GraphIt

  64     1930336  69310426         27  0.07%  0.01%  0.00%   0 Net Input

Thanks

[Giuseppe Larosa]

Hello Rajagopal,

>> CPU utilization for five seconds: 60%/>>>53%<<<<; one minute: 58%; five minutes: 60%

most of cpu usage is caused by interrupts, for this reason you are not finding processes that cause this.

There are packets that are process switched sent to main cpu.

follow the following document for further investigation

http://www.cisco.com/en/US/products/hw/switches/ps708/products_tech_note09186a00804916e0.shtml#ios

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2af0.shtml

You may need to capture traffic destined to the cpu to understand what is happening as explained in first doc

Hope to help

Giuseppe

[Rajagopal Sivaramakrishnan]

Hi Giuseppe

Thanks..

Do we need to capture traffic sourcing the RP ? Need to check if my switch supports local SPAN !... One thing I noticed in "show ip traffic" was I was getting a lot of ICMP unreachables..As said before we do have lots of ACL's denying inbound packets.. not sure if this is related.. we have a change to remove the ACLs today.. WIll keep you posted.. Ill also work on the RP SPAN ...

Regards