Erase a flash from Rommon mode

Hello Friends,

I want to erase all IOS from my flash. I am in ROMMON mode and I can not go to normal Router promt as my IOS is crashed. I am able to download the new IOS from Rommon mode by using tftpdnld or xmodem method.

But after the Image download it is given while decompressing checksum error.

I want to erase whole flash from rommon mode. Does any body know how to erase the total flash or IOS file from rommon mode.

If any body know the command to erase the IOS from flash please please forward it to me...

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Why on earth do you want to do that? A router is not like a computer where you have a registry and little bits get left inside it that will screw other applications. A Cisco router is a nice piece of kit. I suggest that if you want rid of an image you boot up in normal mode and then up/downgrade the unit as normal.

James Flockton wrote:

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James Flockton

When you download the IOS image from CCO, there are checksums for the image listed on CCO. You nshould copy down these values.

I suggest you check that the image did not get corrupted during the download from CCO. To do these verify the checksum of the image after it is on the device that you are going to use for a TFTP server.

After you copy the IOS to you router, verify that the copy was okay by doing a

"dir " and verifying the checksum

Suggest you post the model of the router and the IOS image you are trying to load. That way responders will be in a better position to assist you.

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? a router is a computer

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Which model? ROMMON command vary slightly from unit to unit.

Can you capture the error? Sounds like you either

- Loaded an image which is not compatible with your hardware

- Loaded an image which won't fit in RAM.


- What image name are you loading?

- What hardware is this?

- What is the exact error?

Usually, routers will store the configuration and software in different palces (flash: and nvram:) but there are minor variations by platforms (especially 800 series)

So... More details. The config file will not cause a crash unless there is a specific bug triggered by the config and that almost never ever happens.

If you suspect the config is a problem, you can set the unit to boot up and IGNORE the config file using the confreg command in ROMMON (tell it to ignire config file during the questions).

I suspect your real issue is an incompatible system image loaded into the unit. ROMMON doesn't check compatability.

Also, I have seen some of the older platforms fail with a checksum error even if the image is good. This usually indicates a hardware failure of some fort, either with the flash itself or the flash controller. I saw a few 3800 series suffer this in their flash (slot0:)

Reply to
Phillip Remaker

Yes a router is a computer.... Duh. What do you think it is? A straw hat perchance?

MC wrote:

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