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Ask the Expert: Switch and IOS Architecture and Unexpected Reboots on all Cisco Catalyst Switches

Community Manager
Community Manager

This session will provide an opportunity to learn and ask questions about Cisco Catalyst Switches IOS architecture, and how to troubleshoot any unexpected reboots and other errors on switches.


Ask questions from Monday, October 5 to Friday, October 16, 2015

Featured Experts

Ivan Shirshin is a customer support engineer in High-Touch Technical Services (HTTS). He is an expert on Routing, LAN Switching and Data Center products. His areas of expertise include Cisco Catalyst 2000, 3000, 4000, 6500,  Cisco Nexus 7000, ISRs, as well as Cisco routers ASR1000, 7600, 10000 and XR platforms. He has over 7 years of industry experience working with large Enterprise and Service Provider networks. Shirshin holds a CCNA, CCNP, CCDP, and CCIE (# 43481) in routing and swtiching, as well as XR specialist certifications. 


Naveen Venkateshaiah is a customer support engineer in High-Touch Technical Services (HTTS). He is an expert on Routing, LAN Switching and Data Center products. His areas of expertise include Cisco Catalyst 3000, 4000, 6500,  and Cisco Nexus 7000. He has over 7 years of industry experience working with large enterprise and Service Provider networks. Venkateshaiah holds a CCNA, CCNP, and  CCDP-ARCH, AWLANFE, LCSAWLAN Certification. He is currently working to obtain a CCIE in routing and switching.


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43 Replies 43

Jessica Deaken


We have WS-X6704-10GE  Module along with  WS-F6700-DFC3B, How to identify DFC-Equipped Module Has Reset on its own?


Thank you for your prompt response.




Hi Jessica,

Thanks for raising this question.

If a Distributed Forwarding Card (DFC)-module has rebooted  on its own without user manual reload, you can check the bootflash of the DFC card in order to see if it crashed. If a crash information file is available, you can find the root cause of the crash.

Issue the dir dfc#module#-bootflash: command in order to verify if there is a crash information file and when it was written.

If the DFC reset matches the crashinfo timestamp, issue the more dfc#module#-bootflash:filename command.

We can also issue the copy dfc#module#-bootflash:filename tftp command in order to transfer the file via TFTP to a TFTP server.

cat6kSwitch#dir dfc#6-bootflash:
Directory of dfc#6-bootflash:/
-#- ED ----type---- --crc--- -seek-- nlen -length- -----date/time------ name
1   ..   crashinfo 2B245A6A   C24D0   25   261332 Sep 22 2014 21:35:25 crashinfo_

After you have the crashinfo file available, collect the output of the show logging command and the show tech command and contact you can reach to TAC support to further find the cause of this crash.

Let me know if you have any further doubt.

Naveen Venkateshaiah.

Hi Naveen ,


One of our 6500 switch with sup32 has been reloaded automatically twice. And there were crashinfo files has been generated. In show version command output , the last reset was power on. We tried to use output intrepretor for crashinfo files and there were no relevant results for that. So should we have to raise TAC only for decoding  the files or as we are a partner privileged to use any tools to decode?



Hi Tamil,

Thanks for raising this question,

The Cisco Catalyst 6000/6500 Switches can unexpectedly reload due to an unknown cause. The output of the show version command displays a similar error message:
System returned to ROM by unknown reload cause - suspect
boot_data[BOOT_COUNT] 0x0, BOOT_COUNT 0, BOOTDATA 19 (SP by power-on)

This issue is documented in Cisco bug ID CSCef80423 (registered customers only) . Upgrade the switch to the latest Cisco IOS Software release unaffected by the bug in order to resolve this issue.

  • Normally I would recommend you to check the crash info from both SP and RP ,which is stored in sup-bootflash and boot flash respectively, Look for the respected Time stamp.
  • In the crash info you can also check the crash was due to SP or RP,based on which crashed first.


From SP:

Mar 25 10:46:19.074 GMT: %C6K_PLATFORM-SP-2-PEER_RESET: SP is being reset by the RP    << Here Switch Processor is reset due to Route Processor.

Hence we have to look for RP crash info.

From RP:
Mar 25 10:46:11.166 GMT: %SYSTEM_CONTROLLER-3-ERROR: Error condition detected: TM_NPP_PARITY_ERROR
Mar 25 10:46:11.166 GMT: %SYSTEM_CONTROLLER-3-FATAL: An unrecoverable error has been detected. The system is being reset.

  • There are no tools available to decode the crash info for CCO access,I would request you to raise an SR with Cisco Tac and share both the crash info along with show tech support of the sup which was reloaded.

Let me know if you have any further doubt.

Naveen Venkateshaiah.



Can you please explain the IOS XE images naming convention and how to  identify what is the current version running on my switch?Is there any difference while we run the show commands on IOS and IOS-XE?





  • The naming convention has changed since there are many features that need to be highlighted. Let me give you an example for below  image name:

image name: cat4500e-universalk9.SPA.03.01.00.SG.15-01.SG

 cat4500e: Platform Designator.
 universal: Feature Set Designator.
 k9: Crypto Designator if crypto code is present in IOSd package.
 SPA: Indicates image is digitally signed.
 03.01.00.SG: IOS XE Release Version number.
 15.01.SG: IOSd package version number – this will allow you to correlate the version of IOSd   to another platform running classic IOS

Kernel Version:
cat4500e#show version running
 Package: Base, version: 03.00.00, status: active
 File: cat4500e-basek9.SPA.03.00.00.pkg, on: Slot3
 From Bundle: cat4500e-universalk9.03.01.00.SG

Infrastructure Version
Package: Infra, version: 03.00.00, status: active
File: cat4500e-infra.SPA.03.00.00.pkg, on: Slot3
From Bundle: cat4500e-universalk9.03.01.00.SG

IOSd Version
 Package: IOS, version: 150-1.SG, status: active
 File: cat4500e-universalk9.SPA.15-01.SG.pkg, on: Slot3
 From Bundle: cat4500e-universalk9.03.01.00.SG

  • As IOSd is fully integrated to IOS-XE, feature-level CLI  are quite identical , However there are few Changes do exist in the system management due to underlying Linux.

Below are the Few commands for example:

IOS Command IOS-XE Command   Comments on New CLI 
  • Show proc
  • Show proc cpu detailed iprocess iosd
  • Show proc cpu detailed
  • Identical to classic “show proc”. W/o detailed shows only Linux processes
  • Shows detailed description of all iosd and non-iosd processes across all CPU cores
  • Show proc memory
  • Show proc memory  
  • Show proc memory detailed process iosd   
  • Shows memory util of entire system
  • Shows memory usage by iosd process
  • Show proc cpu history
  • Show proc cpu history summary
  • Show proc cpu history
  • Shows overall CPU Utilization of the platform similar to single core classic IOS
  • Shows CPU utilization by core


Naveen Venkateshaiah.

Ivan Petrov

Hello Ivan and Naveen,

We are getting this error message: “%CFIB-7-CFIB_EXCEPTION: FIB TCAM exception, Some entries will be software switched”

We could not find what is the meaning of this error in the documentation. Can you  let me know what it means and if there is anything I should do in order to stop receiving it?

Thank you,