High CPU utilization

Unanswered Question
May 18th, 2010

Hi

I am facing a prolem my cpu utilization goes high intermittenly

my router has ios : c2600-ipbase-mz.123-26.bin

Model: cisco 2621XM

plz find the" show pro cpu" its show 99% , also plz ignore the virtual exec process as this i have used to generate the show tech outout.

I have to removed the show run due to security issue.

I m using multilink can that be a reason and also load i doubt in the link load also, can someone plz comment on muy onbservation.

Thaks in advance

I have this problem too.
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Laurent Aubert Tue, 05/18/2010 - 14:29

Hi,

So from what you said the CPU spikes are correlated to an unknown recurrent event right ? Do you have SNMP polling in place ? Any instability with your routing protocol ? Any script running an a regular basis which could poll the router as well ?

Do you have cef enabled ?

HTH

Laurent.

rupam_chakra1983 Tue, 05/18/2010 - 19:27

Hi

Yes cef has been enabled and  i can see high cpu utilization in the " show proc cpu" but not able to trace the exact process that is causing high cpu.

I have seen in the cisco output inter[retter and it show load is due to interrupt and is caused by high traffic but i want to analyze which IP s are generating high traffic what steps or command output will help me in analyzing the same.

In the " show interface switching" shows:

show interfaces switching
FastEthernet0/0
          Throttle count          0
                   Drops         RP          0         SP          0
             SPD Flushes       Fast          0        SSE          0
             SPD Aggress       Fast          0
            SPD Priority     Inputs      41528      Drops          0

    Protocol  IP                 
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process      53922    5326429      83037   36967369
            Cache misses      65673          -          -          -
                    Fast  102813512 2249272985   95996295 1668803525
               Auton/SSE          0          0          0          0

    Protocol  DEC MOP            
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process          0          0        266      20482
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    Protocol  ARP                
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
Process      41522    2491320        291      17460
Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    Protocol  Other              
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process       5292     296352      15829     949740
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    NOTE: all counts are cumulative and reset only after a reload.

======================================

FastEthernet0/1

         Throttle count          0
                   Drops         RP          0         SP          0
             SPD Flushes       Fast          0        SSE          0
             SPD Aggress       Fast          0
            SPD Priority     Inputs       1070      Drops          0

    Protocol  IP                 
--More--                     Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process     143652   85012905     101498   53325996
            Cache misses        906          -          -          -
                    Fast   95700365 1869229308  102494868 1962945539
               Auton/SSE          0          0          0          0

    Protocol  DEC MOP            
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process          0          0        266      20482
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    Protocol  ARP                
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process         14        840         38       2280
            Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

    Protocol  Other              
          Switching path    Pkts In   Chars In   Pkts Out  Chars Out
                 Process          0          0      15829     949740
Cache misses          0          -          -          -
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

Thnaks

Laurent Aubert Wed, 05/19/2010 - 06:53

Hi,

Here are some links that will help you into the troubleshooting process:

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

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2af3.shtml

In addition to that, you can try capturing packets which are punted to the CPU with the sh buffer input-interface header | packet. You need to run this command several times during the high CPU issue as you will not capture a packet each time.

Also you could activate netflow which will give you a list of all the flow going through the router. It may help you identify unexpected traffic. Finally show ip traffic will give you detailed statistics.

HTH

Laurent.

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