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Cisco IOS Software Releases 12.0 Mainline

ROMmon Recovery for the Cisco 4500 and 4700 Series Routers

Cisco - ROMmon Recovery for the Cisco 4500 and 4700 Series Routers

Document ID: 15072

Updated: Jan 23, 2008

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Introduction

This page describes the procedure to recover Cisco 4500 and 4700 Series Routers stuck in ROMmon (rommon# > prompt).

Before You Begin

Conventions

For more information on document conventions, see the Cisco Technical Tips Conventions.

Prerequisites

There are no specific prerequisites for this document.

Components Used

The information in this document is based on the hardware versions below:

  • Cisco 4500 and 4700 Series Routers

The information presented in this document was created from devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If you are working in a live network, ensure that you understand the potential impact of any command before using it.

Looking for a Valid Image in Flash:

Follow the instructions provided below:

  1. Issue the dev command to see which devices are available on your router:

    rommon 1 > dev 
    Devices in device table:
            id  name 
        flash:  flash 
    bootflash:  boot flash 
        eprom:  eprom
    rommon 2 > 
  2. Issue the dir flash: command, and then look for a valid Cisco IOS® software image:

    rommon 3 > dir flash:
             File size              Checksum   File name
          8052512 bytes (0x7adf20)   0xc7b6    c4500-js-mz.121-6
    rommon 4 >  
    

    You can also use the dir bootflash:command to examine the bootflash for a valid boot image.

  3. Try to boot from that image. If the file is valid, this brings you back to normal operation mode:

    rommon 5 > boot flash:c4500-js-mz.121-6
    program load complete, entry point: 0x80008000, size: 0x7ade04
    Self decompressing the image : #####################################      
    ####################################################################      
    ####... 
  4. If none of the files are valid, you need to download a new one. There is only one way to install an image on the Cisco 4500 and 4700 Series Routers if the main Cisco IOS software has been deleted or corrupted: use the router's boot image.

Download Using the Boot Image and a Trivial File Transfer Protocol (TFTP) Server

For detailed instructions on this procedures, see How to Upgrade from ROMmon Using TFTP with Boot Image.

If both the main image and the boot image are corrupted or deleted, there is no easy way to recover the router. Aside from a return materials authorization (RMA), the only other option is to swap flash single in-line memory modules (SIMMs) from another 4500 or 4700 router that has a valid boot image and a main Cisco IOS software.

Related Information

Updated: Jan 23, 2008
Document ID: 15072