Cisco Cisco IOS Software Release 12.0(2a)T1 Guia De Resolução De Problemas

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The router should now reload with a valid Cisco IOS software image.

If the configuration register value is set to make the system boot automatically from a default Cisco IOS
software image, and if no break signal is sent during start up, the router should boot normally. However, if the
router still enters the ROMmon mode, it is probably because the device is unable to locate a valid Cisco IOS
software image.

The first thing you need to do then is to look for a valid Cisco IOS software image. To do this, issue the dir
<device> command for each available device, and look for a valid Cisco IOS software image. For example, to
look for the IOS in the Flash, use the command shown below.

rommon 1 > dir flash:

         File size         Checksum   File name   

5358032 bytes (0x51c1d0)   0x7b16    c2600−i−mz.122−10b.bin

rommon 2 >

Note that if the router returns the "bad device name" message, the device specified probably does not exist.
The output above indicates that a valid image is indeed present in the Flash. Try to boot from that image using
the boot command.

rommon 2 > boot flash:c2600−i−mz.122−10b.bin

program load complete, entry point: 0x80008000, size: 0x51c0dc

Self decompressing the image : #################################################

##################################

...

The router should now boot with the Cisco IOS software image specified in the boot command. However,
there are times when a valid image does not exist on any of the devices or the image on the Flash might be
corrupted. In these cases, a valid image has to be downloaded using Trivial File Transfer Protocol (TFTP) or
by using the Xmodem procedure. Both these procedures can be carried out from the ROMmon mode.

Note: There are instances where the system message "Device does not contain a valid magic number"
appears. If this happens, in addition to getting a valid Cisco IOS software image, you might need to reseat the
Flash or replace it, if it is damaged.

This is the fastest way to re−install a new Cisco IOS software image on the router. Go to Using the tftpdnld
Command.

You can also download a new Cisco IOS software version through the console port, using Xmodem. Go to
Xmodem Console Download Procedure Using ROMmon.

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