Accidently Format the FLASH FileSystem of Cisco Switch 3750

Unanswered Question
Nov 22nd, 2008

Dear Friends,

I am using Switch 3750 of upgrading its software but accidently i format FLASH filesystem that make my switch unusable. Can anybody tell me how to solve this problem. It's seem now that i am not able to use the Switch.


Faisal Mubarak

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viyuan700 Sun, 11/23/2008 - 01:37


Dont worry i hope you have IOS for ur switch if yes then u can transfer that IOS image from http terminal to ur switch through ROMMON mode. I am attaching a file which explain the process though i used it for 3500. I hope same will work for u or u can search for 3750 switch on cisco site.

If you dont have IOS image then wither downlaod from cisco website if u have access or u can TFTP from another switch to ur PC/laptop then can transfer to the switch which u have formatted.

Joseph W. Doherty Sun, 11/23/2008 - 03:54

As Vishwamurti's notes, this information is available (somewhere) on Cisco's web site. (It might be worth checking you have the documention for the 3750.)

In short, you're going to enter a special ROM mode (actually without an IOS in flash, device should boot into that automatically), and load the IOS image via your console cable.

Some hints that might be overlooked, to speed up the load, i.e. decrease the time (which can run into the hours when using defaults), use the best transfer protocol supported between your console client and the 3750 (belive the 3750 supports xmodem and xmodem-1k, you'll want to use the latter). Second, default console speed is usually 9.6K but you'll want to increase this to the maximum supported by both your client and the 3750.

Something else to watch for is whether the 3750 loads the IOS into flash or directly boots into it. For the former, you may need to explicity use some boot command (or perhaps power restart), for the latter, your 3750 will be running the new image so you'll want to get an image loaded as quickly as possible into flash (load image via the network).


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