Router/Switch CPU info

[Bab L]

Hi all.

Just a quick question.

If someone asks you to provide them with the below information for devices how would you find that information? What is the right command? Cannot find anything on the net that makes it clear.

Router/Switch CPU

Router/Switch OS

Router/Switch Memory

Thank you

[Vinit Jain]

Usually you can find all the information on the show version command of the router / switch on Cisco platforms. The show version command displays the OS running on the router, memory / DRAM available on the router and also shows the CPU / processor version on certain code versions.

Though, if you are looking for verifying the memory utilization, using the command show memory summary or show memory statistics. If you are looking for verifying the current CPU utilization, use the command show process cpu sorted.

Hope this helps

Regards

Vinit

PS: Please rate useful posts. ALso, mark the question as answered if your query has been resolved.

[Bab L]

Thanks Vinit.

I'm aware of all this info. My question is more coming from a non technical person.

If someone comes up to you and asks you how much cpu does our 2901 router has where would you find the answer?

[Vinit Jain]

From that perspective, for every platform there is a data sheet that can be referred for such details. This is usually viewed before buying any router / switch to understand its scale and capacity. For example, for Cisco 2901 platform: 

http://www.cisco.com/c/en/us/products/collateral/routers/2900-series-integrated-services-routers-isr/data_sheet_c78_553896.html

Hope this helps

Regards

Vinit

[Bab L]

Thanks Vinit.

Already looked at that page. It does not provide CPU information.

[Vinit Jain]

the only reason for not having this information is that there are platforms, which have multiple variations to it. Such as 2900 series router, has 2901, 2911, 2921, etc. The data sheet is for the platform and not for each variation of the platform. Thus it will only show generic information such as in this case multi-core CPU. I have seen some data sheets which shows the information of the CPU such as ASR1k ESP card:

http://www.cisco.com/c/en/us/products/collateral/routers/asr-1000-series-aggregation-services-routers/datasheet-c78-731640.html

But again, the information varies based on their performance metrics and the CPU information is not very precise in documentation.

if you are trying to explain someone who is non-technical, the best way to convey the capability of the CPU would be in terms of throughput the CPU can handle or number of packets processed per second.

Regards

Vinit

[Bab L]

Thanks for your help Vinit.

[e.ciollaro]

Hi Bab,

I agree with Vinit, CPU is not the most important thing because routers' performance does not strictly depend on CPU, usually Cisco routers use CEF switching and CPU is not involved in routing.

If you have to proof router's performance use the attached datasheet (old but still useful).

Bye,

E

PS: please rate if useful

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages wha2tsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

. . . CPU is not the most important thing because routers' performance does not strictly depend on CPU, usually Cisco routers use CEF switching and CPU is not involved in routing.

Perhaps you're thinking of L3 switches or high end routers with extra hardware support.  On the lower end routers, such as ISRs in your reference link, the CPU does everything including CEF switching.

[e.ciollaro]

Hi Joseph,

I thought ISR G2 had a dedicated ASIC for CEF :-(

In any case what I was trying to explain is that the knowledge of the CPU onboard is not the right way to understand router's performance; for example routing performance can greatly change using different switching algorithm (process switching Vs CEF)  or activating a specific feature.

Thank you for your valuable post, bye 

E

[Bab L]

Thanks everyone for your posts.

My question was based on an answer that non IT person wanted. They just wanted to know CPU information for a 2901 router. That's it. I'll just tell them to add N/A:-)

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages wha2tsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Routers and switches are, more or less, closed architectures.  In theory, a vendor like Cisco might use a different hardware components for a later variant of the same device.  So, they generally don't "advertise" what CPU or clock rate a router or switch is using.  This would also apply to the support chips and mod level of other different hardware components.  All that Cisco "guarantees" is any 2901 should perform and behave like other 2901 regardless of what hardware components are within it.  (NB: occasionally internal components do become important if there's some hardware defect in certain hardware.  Vendors will then usually provide some way for you to identify whether your model is affected.)

Router and switch OSs are generally loaded from flash and a running version is usually easily identified using the show version command.  Assuming an OS's filename hasn't been changed, that too will identify it.

Memory capacity, both flash and RAM, is usually also easily revealed with different show commands, because such capacity often has bearing on device's usage, and also many platforms support different memory capacities (often field upgradable).  (NB: Like CPU info, generally vendors don't reveal the actual kind of RAM or flash.)