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3750 IOS deleted

Geoffrey FROST

I have a 3750 which I deleted the IOS on Friday and then powered it off for the weekend.

THe proceedure to recover it: uses load_helper and copy xmodem, neither of which I appear to have. Any ideas? The switch is a 3750G-12S.           

7 Replies 7


Load_helper is part of the rommon code on the switch and is just part of the procedure to recover.  XModem is available on most terminal emulators whether  hyperterm. Tera Term or Putty  .  Follow the doc and you should be able to recover the switch.

Geoffrey FROST

Thanks for the reply, Glen.

The Load_helper command is not on my switch. I will have a look at the options on my hyperterm help.



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If you do load an IOS via the console port, you might want to push the console's fastest rate supported both by the 3750 and the host you're using.  Also, use the "fastest" transfer protocol that your comm program and 3750 share, e.g. xmodem-1k (?).  Lastly, you might want to load the smallest IOS image you can find, to get the device on-line, then flash it across the network with the intended IOS.


Thanks for the help.

The load helper, what does it do? I used xmodem from the hyper term and reloaded the bin over night. So I have my last of 50 switches upgraded.

I think the doc is a bit out of date for the current revision of boot software, but it still works.

job done, thanks again.


Peter Paluch
Hall of Fame Cisco Employee Hall of Fame Cisco Employee
Hall of Fame Cisco Employee

Hi Geoffrey,

The load_helper command was used on certain platforms to load and initialize a boot helper IOS image. This image supposedly allowed you to access hardware, modules and line cards that the bootloader itself did not recognize. However, on most fixed-configuration switches like 2950/2960/3550/3560/3750, the load_helper command actually did nothing - there is no concept of a boot helper image on these platforms - and most recent bootloaders do not even contain this command.

So if it is not available, don't worry - it wasn't doing anything anyway.

Best regards,


The Load_helper command is not on my switch.

Console into the switch and reboot the switch.  Post the entire bootup process.  Also enter the command "?" and hit enter.

You should have the command flash_init.  If you see this, enter this command.


My switch ws-c3750-24ps-p v05 also has no iOS and also no load_helper.  There are only two files: flash_init and boot.  I can't even installed iOS image in the system when I use Putty.  What can I do to achieved or make it work?  


Boot can't process and failed

CCCC???.bin(file name): i/o error


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