The router reports the device does not contain a valid magic number error message and fails to load the Cisco IOS Software image

[TCC_2]

Core Issue

In this case, the file system on the device from which the CPU tries to load the Cisco IOS  Software image is corrupted.

Resolution

Depending on the router model, choose from these resolution options:

• Boot from another Flash device.
• Boot from the TFTP server.
• Issue the xmodem command in order to download the image. Refer to Xmodem Console Download Procedure Using ROMmon for the procedure to download the image.   
  

If the router platform is c1600, c2500, or c5200, it eventually loads the boot image.

If the router platform is c4000, c4500, c4700, c7200, c7500, or AS5800, ideally it eventually loads the boot image as well unless the bootflash is corrupted.

This is an example of what the prompt on the router looks like:

Router(boot)>

Where Router is replaced with the hostname of your router.

In order to resolve this issue, perform these steps:

1. Issue the enable command to go to enable mode.     
2. If the router is a c7200, c7500, or AS5800 platform, issue the format command in order to format the appropriate Flash device (flash:, slot0:, slot1:, disk0: or disk1:). 

   On low-end platforms, there is no need to format the Flash.

3. Issue the copy command in order to download the Cisco IOS Software image from a TFTP server.     
4. If the TFTP server is not in a directly attached network, the default gateway must be configured. Issue the ip default-gateway configuration command to do this.

   Note: Do not save the configuration while in boot mode, because all the information about routing, such as static routes and dynamic routing protocol configuration, is lost.

      

If the router is a c2600, c3600, or AS5300 series, it falls into ROM Monitor (ROMmon) mode. Use these options in order to resolve this issue:

• Issue the xmodem ROMmon command in order to download the Cisco IOS Software image to the Flash.  
  
• On c2600 routers, refer to How to Download a Software Image to a Cisco 2600 via TFTP Using the tftpdnld ROMMON Command.

Note: The ROMmon variables that have to be configured are case sensitive.

If the router is a c4000, c4500, or c4700 Series and falls into ROMmon mode, refer to ROMmon Recovery for the Cisco 4500 and 4700 Series Routers.  

If the router is a c7200, c7500, or AS5800 Series and falls into ROMmon mode, refer to ROMmon Recovery Procedure for the Cisco 7200, 7300, 7400, 7500, RSP7000, Catalyst 5500 RSM, uBR7100, uBR7200, uBR10000, and 12000 Series Routers.