IOS 12.4-15.T1 High CPU Usage from Show Run CLI

Unanswered Question
Aug 14th, 2007


I recently upgraded a 2811 to 12.4-15.T1 and since doing that, I receive High CPU usage from a "Show Run" command. This never happend in the past.

This router has 512MB DRAM, so I'm hoping there's no shortage along these lines.

Attached is the outoupt (excluding 0.00%) from sh cpu process which hopefully will give some insight - output shows Virtual Exec as the culprit.

Any ideas?

I have this problem too.
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Paolo Bevilacqua Tue, 08/14/2007 - 05:25

Any particular reason fro using 12.4(15)T1?

You will find that newer releases often have changed behavior and something plain bugs causing havoc.

kst.amand Tue, 08/14/2007 - 05:35

We are working with GDOI/GETVPN, which started with 12.4(11)T.

We were encountering a CEF SNMP error introduced with 12.4(11)T2 which caused us to upgrade from that version.

Fortunately, the High CPU usage appears to be short lived and non-service affecting.

thomas.anthony Tue, 08/14/2007 - 05:50

if you see your cpu output VTY is the one using the max cpu.check if the debug is enabled and output has been redirected to the vty(using the terminal monitor or the no logging console command), the amount of CPU

resources used by the virtual EXEC process increases

82 6008 1279 4697 90.94% 9.45% 1.00% 514 Virtual Exec

thomas.anthony Tue, 08/14/2007 - 05:52

also 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.

kst.amand Tue, 08/14/2007 - 06:07

No debugging is currently defined, also verified with "un all".

"No logging console" issued, still getting same high cpu usage.

I have a test router on a bench, no network connectivity, so I wouldn't expect any type of security issue. I get this same high CPU usage.

Any other thoughts?

Thank you for the feedback.


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