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SOS ... 100% CPU Procesing

Hi to all this is a router with 3 E1s that is having high procesing performance and some call are being dropped. Any suggestion? i will be grateful.

Thanks in advanced.

Pepe

PD: I am attaching the sh tech

1 ACCEPTED SOLUTION

Accepted Solutions

Re: SOS ... 100% CPU Procesing

Here is the Output Interpreter information for your routers sh tech/cpu utilization. You might want to plug this in yourself and get the full report. This is probably the first thing you want to use to start diagnosing your issue if you don't see an obvious process hogging cpu, as is the case in your sh tech. The CPU interrupts seem to be the main culprit, follow the documentation below for starting points on troubleshooting this.

https://www.cisco.com/cgi-bin/Support/OutputInterpreter/home.pl

------------------------

CPU UTILIZATION ANALYSIS

------------------------

INFO: Total CPU Utilization is comprised of process and interrupt percentages.

Total CPU Utilization: 99%

Process Utilization: 28%

Interrupt Utilization: 71%

These values are found on the first line of the output:

CPU utilization for five seconds: x%/y%; one minute: a%; five minutes: b%

Total CPU Utilization: x%

Process Utilization: (x - y)%

Interrupt Utilization: y%

Process Utilization is the difference between the Total and Interrupt; x minus

y. The one and five minute utilizations are exponentially decayed averages (rather

than an arithmetic average), therefore recent values have more influence on the

calculated average.

ERROR: Total CPU Utilization is at 99% for the past 5 seconds, which is very

high (>90%).

This can cause the following symptoms:

- Input queue drops

- Slow performance

- Slow response in Telnet or unable to Telnet to the router

- Slow response on the console

- Slow or no response to ping

- Router doesn't send routing updates

The following processes are causing excessive CPU usage:

PID CPU Time Process

3 15.82 Virtual Exec

INFO: The 'virtual EXEC process' handles virtual type terminal (vty) lines,

such as Telnet sessions on the router.

INFO: Issuing commands that generate long output, such as 'show tech-support',

can also increase the amount of CPU resources used by the virtual EXEC process.

NOTE:

- Make sure all debugging commands in your router are turned off by issuing

the undebug all or no debug all command.

- Check for a possible security issue. Commonly, high CPU utilization is caused

by a security issue, such as a worm or virus operating in your network. Usually,

a configuration change, such as adding additional lines to your access lists

can mitigate the effects of this problem. Check the Cisco Product Security Advisories

and Notices for information on the most likely causes and specific workarounds.

REFERENCE: For more information, see Troubleshooting High CPU Utilization Due

to Interrupts.

REFERENCE: For troubleshooting information, please visit

Troubleshooting High CPU Utilization on Cisco Routers

WARNING: Interrupt CPU Utilization is 71%, which is very high (>60%) CPU interrupts

are primarily caused by fast switching of traffic. Interrupts are also generated

any time a character is output from the console or auxiliary ports of a router.

TRY THIS: One of the following may be causing this to happen:

- The CPU is performing memory alignment corrections. If there are

%ALIGN-3-CORRECT messages logged, then the high CPU utilization is caused by

memory alignment corrections. Capture the output of the 'show align' command,

decode the tracebacks and search for a bug in your version of IOS. Contact

Cisco TAC for further assistance.

- There maybe a bug in the version of IOS running on the router. Check the Bug

Toolkit

for a bug that reports similar symptoms in a similar environment.

REFERENCE: For additional troubleshooting information, please visit Troubleshooting

High CPU Utilization on Cisco Routers

Please rate any helpful posts

Thanks

Fred

2 REPLIES

Re: SOS ... 100% CPU Procesing

Here is the Output Interpreter information for your routers sh tech/cpu utilization. You might want to plug this in yourself and get the full report. This is probably the first thing you want to use to start diagnosing your issue if you don't see an obvious process hogging cpu, as is the case in your sh tech. The CPU interrupts seem to be the main culprit, follow the documentation below for starting points on troubleshooting this.

https://www.cisco.com/cgi-bin/Support/OutputInterpreter/home.pl

------------------------

CPU UTILIZATION ANALYSIS

------------------------

INFO: Total CPU Utilization is comprised of process and interrupt percentages.

Total CPU Utilization: 99%

Process Utilization: 28%

Interrupt Utilization: 71%

These values are found on the first line of the output:

CPU utilization for five seconds: x%/y%; one minute: a%; five minutes: b%

Total CPU Utilization: x%

Process Utilization: (x - y)%

Interrupt Utilization: y%

Process Utilization is the difference between the Total and Interrupt; x minus

y. The one and five minute utilizations are exponentially decayed averages (rather

than an arithmetic average), therefore recent values have more influence on the

calculated average.

ERROR: Total CPU Utilization is at 99% for the past 5 seconds, which is very

high (>90%).

This can cause the following symptoms:

- Input queue drops

- Slow performance

- Slow response in Telnet or unable to Telnet to the router

- Slow response on the console

- Slow or no response to ping

- Router doesn't send routing updates

The following processes are causing excessive CPU usage:

PID CPU Time Process

3 15.82 Virtual Exec

INFO: The 'virtual EXEC process' handles virtual type terminal (vty) lines,

such as Telnet sessions on the router.

INFO: Issuing commands that generate long output, such as 'show tech-support',

can also increase the amount of CPU resources used by the virtual EXEC process.

NOTE:

- Make sure all debugging commands in your router are turned off by issuing

the undebug all or no debug all command.

- Check for a possible security issue. Commonly, high CPU utilization is caused

by a security issue, such as a worm or virus operating in your network. Usually,

a configuration change, such as adding additional lines to your access lists

can mitigate the effects of this problem. Check the Cisco Product Security Advisories

and Notices for information on the most likely causes and specific workarounds.

REFERENCE: For more information, see Troubleshooting High CPU Utilization Due

to Interrupts.

REFERENCE: For troubleshooting information, please visit

Troubleshooting High CPU Utilization on Cisco Routers

WARNING: Interrupt CPU Utilization is 71%, which is very high (>60%) CPU interrupts

are primarily caused by fast switching of traffic. Interrupts are also generated

any time a character is output from the console or auxiliary ports of a router.

TRY THIS: One of the following may be causing this to happen:

- The CPU is performing memory alignment corrections. If there are

%ALIGN-3-CORRECT messages logged, then the high CPU utilization is caused by

memory alignment corrections. Capture the output of the 'show align' command,

decode the tracebacks and search for a bug in your version of IOS. Contact

Cisco TAC for further assistance.

- There maybe a bug in the version of IOS running on the router. Check the Bug

Toolkit

for a bug that reports similar symptoms in a similar environment.

REFERENCE: For additional troubleshooting information, please visit Troubleshooting

High CPU Utilization on Cisco Routers

Please rate any helpful posts

Thanks

Fred

New Member

Re: SOS ... 100% CPU Procesing

Thanks Fred that was an extremely nice tool. Thank you very much, now i will analize the data

Pepe

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