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Cisco 3750-X high cpu & %SSH-4-SSH2_UNEXPECTED_MSG, %SYS-3-CPUHOG messages


We have two WS-C3750X-24T-S switches in stack. We are experiencing CPU utilization on higher side > 70% & also getting below log messages when trying to SSH the switch & execute show tech-support command.

%SSH-4-SSH2_UNEXPECTED_MSG: Unexpected message type has arrived. Terminating the connection

%SYS-3-CPUHOG: Task is running for (2115)msecs, more than (2000)msecs (144/98),process = SSH Process.

-Traceback= 0x1A73C20z 0x1A1E0C0z 0x1A4E3C8z 0x28384DCz 0x17F1908z 0x17F1F38z 0x4507DCz 0x49ACFCz 0x1802D58z 0x17F4EE8z 0x26D5768z 0x26CF5DCz

CPU utilization for five seconds: 70%/34%

SSH Process = 18.55%

IP Input = 2%

Hulc LED Process = 3.51%

hpm counter proc = 1.43%

hpm main process =  0.31%

IOS: c3750e-universalk9-mz.122-58.SE2.bin.

Can any one let me know what's the issue & how it is related to CPU utilization.

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Cisco 3750-X high cpu & %SSH-4-SSH2_UNEXPECTED_MSG, %SYS-3-CPUHO

Do you observe this only when you are executing show tech or do you observe these symptoms at other times?

When you execute show tech it runs a process that executes many show commands and collects much data to include in the command output. This would be very CPU intensive.

If the only time that you experience the symptoms is during execution of show tech, then I would say that you do not have much to worry about. If you experience these symptoms at other times then perhaps there is more of an issue that could cause concern.

To start with the easy part of the symptom, let us start by thinking about the traceback message. Only Cisco has the tools to decode that message and really understand what it is saying. But one thing we can say for sure is that a traceback is always the result of a software issue. And it is the way that Cisco reports back to itself about the software issue. So if you are experiencing traceback messages then your software in encountering some issue. We can not say for sure what the issue is but we can say that the way to address the traceback is to update the version of code that the switches are running.

The CPUHOG message is fairly clear. It is saying that some process is consuming a lot of CPU cycles. If it is only encountered during show tech then probably we understand why it is generated. If encountered in other situations then there is something else going on. I would guess that the CPUHOG message is probably related to the traceback issue. And that upgrading the version of code will probably also address the CPUHOG message.

I do not believe that the SSH message is realted to the other two messages. And I do not believe that the SSH message is a cause of concern. I see that kind of message from time to time at customer sites and I have never found that it pointed to anything that was causing a real problem.




Cisco 3750-X high cpu & %SSH-4-SSH2_UNEXPECTED_MSG, %SYS-3-CPUHO

This is a KNOWN issue.  Running the latest code version will NOT fix it either.

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