Solved: Router boots with wrong IOS

Muhammad Kashif Siddiqui · ‎05-25-2015

I am having one 3825 Router for which I planned to change one of the faulty FAN. After replacing I powered on the Router and it booted with the wrong IOS "c3825-advipservicesk9-mz.124-9.T6.bin" instead "c3825-advipservicesk9-mz.124-24.T5.bin ". I am using "boot system url-path" command instead "boot system flash url-path" command. Please confirm what can be the possible issue since I have already consulted so many documents but have not found any clue.

Config-Register:

show version

Configuration register is 0x2102

Partial Running-Config:

boot-start-marker
boot system flash:c3825-advipservicesk9-mz.124-24.T5.bin
boot-end-marker

Dir Flash Output:

Router#dir
Directory of flash:/

    1 -rw-    41080124 Jan 26 2008 01:17:16 +04:00 c3825-advipservicesk9-mz.124-9.T6.bin
   11 -rw-    60423188 Nov 24 2011 18:20:52 +04:00 c3825-advipservicesk9-mz.124-24.T5.bin
   12 -rw-         660 Feb 18 2015 15:16:00 +04:00 vlan.dat

http://www.lab.dit.upm.es/~labrst/config/ciscopedia/boot%20system.htm

https://www.safaribooksonline.com/library/view/cisco-ios-cookbook/0596527225/ch01s08.html

http://routing-bits.com/2009/10/11/bootsystem/

acampbell · ‎05-25-2015

Hi,

I Tend to agree with Leo. :)

Try verifying you prefeerd IOs

verify /md5 flash:c3825-advipservicesk9-mz.124-24.T5.bin

According to CCO your MD5 result should be:-
22e20b3bad8d2771f068267046ecbbde

Regards
Alex

Regards, Alex. Please rate useful posts.

View solution in original post

Leo Laohoo · ‎05-25-2015

On a router, none. Just "sh run" will give you the output.

On a switch, the command is "sh bootvar".

View solution in original post

Leo Laohoo · ‎05-25-2015

Maybe the IOS is corrupt.

acampbell · ‎05-25-2015

Hi,

I Tend to agree with Leo. :)

Try verifying you prefeerd IOs

verify /md5 flash:c3825-advipservicesk9-mz.124-24.T5.bin

According to CCO your MD5 result should be:-
22e20b3bad8d2771f068267046ecbbde

Regards
Alex

Regards, Alex. Please rate useful posts.

Muhammad Kashif Siddiqui · ‎05-25-2015

I verified the checksum it was OK.

Issue fixed once I removed the second IOS "c3825-advipservicesk9-mz.124-9.T6.bin" from Flash and it booted from my desired IOS "c3825-advipservicesk9-mz.124-24.T5.bin". Currently I only have one IOS in my flash.

I believe there is some problem with "boot system" command which I have entered. Can you explain what is the exact difference of using the "flash" keyward before "url-path"

Like what is the difference between below two commands ?

1- boot system flash:c3825-advipservicesk9-mz.124-24.T5.bin

1- boot system flash flash:c3825-advipservicesk9-mz.124-24.T5.bin

Leo Laohoo · ‎05-25-2015

The second command is incorrect. The correct syntax is "boot system flash:IOS.bin". The second command is correct if you're dealing with 6000/6500 system.

Muhammad Kashif Siddiqui · ‎05-25-2015

Hi Leo,

Thanks for your response. Do we have any command which can show us current "boot loader register" value just like we have "show bootvar" since I cannot see this command in 3825.

Thanks/Regards

Leo Laohoo · ‎05-25-2015

On a router, none. Just "sh run" will give you the output.

On a switch, the command is "sh bootvar".