ASR-9K CPU troubleshooting

Micah Croff micahcroff at
Tue Apr 19 23:17:00 UTC 2016

I've experienced similar behavior on other platforms as well.  Sometimes
the output of the box is not correct.  We were able to prove this to the
vendor by conducting experiments and graphing the CPU.  One of the
protocols they said "couldn't possibly be causing this" turned out to be
the root of the problem.

I live by one rule when troubleshooting:
The box is a lie.


On Tue, Apr 19, 2016 at 4:06 PM, Laurent Dumont <admin at>

> It coincides with nothing else? More traffic? CPU increasing at regular
> intervals every day without any obvious reasons is probably something worth
> looking into!
> On 4/18/2016 2:14 PM, Scott Weeks wrote:
>> --- regezos at wrote:
>> From: Rukka Pal <regezos at>
>> How do you guys troubleshoot high CPU utilization on the ASR-9K platform?
>> Detailed guides are available for IOS platforms, but I can't seem to find
>> anything useful for the ASR.
>> The average line-card (0/0/CPU0: A9K-24x10GE-TR) CPU utilization of my
>> routers is about 10%, however recently I have noticed that 3-5 times a day
>> it increases to 40% and stays there for about an hour (20% spp + 10% netio
>> + the rest).
>> I know this is well withing the acceptable range, but I am the kind of
>> person who likes to understand every change in his network and during the
>> investigation I had to realize that I simply don't have the tools to
>> troubleshoot the ASR CPU.
>> -----------------------------------
>> On cisco: sho proc cpu
>> scott

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