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how to upgrade IOS


1. I have cisco 4503 sup II+TS and there is no external flash in this switch. when I enter show bootflash: and enter it shows the image which is installed. Now it is having 32 Mb of Memory.

I have upgraded the IOS of routers and switch which are hacing external flash but never on bootflash. Can someone tell me the process to upgrade the ios in BOOTflash.

2. one more query with other switch of same model. when we hardboot our switch it donot boot properly and goes to rommon mode, then we have to put boot commant at the prompt then it starts booting.

I think there is some problem with the boot sequence. we donot have flash in switch and IOS resides in bootflash. Please provide suggestions.

boot system tftp cat4500-ipbasek9-mz.122-44.SG.bin
boot system flash cat4500-ipbasek9-mz.122-44.SG.bin

3. In some 8750 or 2960 switches when they got hardbooted due to power failure and during startup they show error with "image name in switch" and again start booting. and sometime they finish to boot properly and some time they donot. we have to put boot or reload command again on failed switches.

Please comment on these problems




Re: how to upgrade IOS

Hello Hemant,

1. The procedure is quite the same (with slight differences) between an upgrade and boot from external flash & from bootflash.

The upgrade details are explained in the release notes of the version you will upgrade to :

For example :

/ Use the dir bootflash: command to ensure that there is sufficient space in Flash memory to store the.

/ If there is insufficient space, delete one or more images, and then enter the squeeze bootflash: command to reclaim the space.

-Switch# copy tftp: bootflash:


I think indeed it has to do with boot sequence. Use the show bootvar command to verify the boot string

In your case I see the two lines :

boot system tftp cat4500-ipbasek9-mz.122-44.SG.bin => Booting 122-44.SG from a tftp server
boot system flash cat4500-ipbasek9-mz.122-44.SG.bin                        => Booting 122-44.SG ...bootflash is not specified. Correct sentence is "boot system flash bootflash:cat4500........" or the IOS is not present in your bootflash..

If you want to modify these lines enter the commands the 'no boot' commands in order to clear the line, then do a write, verify the status with show bootvar, and enter again the accurate line

Switch# configure terminal
Switch(config)# no boot system flash bootflash:cat4500-xxxxxxxxxyyyyyyyyy
Switch(config)# exit
Switch# write
Switch# configure terminal
Switch(config)# boot system flash bootflash:yyyyyyyyy
Switch# write Switch# show bootv


About the last, the better I think would be to show us a capture of the boot sequence (epsecially when they do not boot correctly) and show what message you want to know about.

Thanks and regards.


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