This document describes how to recover a Cisco 800 series router if you are blocked in TinyRom (the boot# prompt).
There are no specific requirements for this document.
This document is not restricted to specific software and hardware versions.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
For more information on document conventions, refer to the Cisco Technical Tips Conventions.
First, determine whether you still have a valid Cisco IOS® Software image in Flash.
Use the list command to display the files stored in Flash:
boot# boot# list Status Size Dev Name ------ 48K flash TinyROM-1.0(2) ------ 48K flash TinyROM-1.0(3) --Dr-x 2600K flash c800-y6-mw.120-5.T ---r-x 2863K flash c800-y6-mw.121-5 !--- Here it is 5184K free 8192K total boot#
The image is valid if it has a status of "---r-x".
If the "x" is not present, the image is probably corrupted, and needs to be deleted. Use the delete [filename] command to mark it as deleted, and the erase command to effectively delete all files marked deleted.
If "D" is present, the image has been marked deleted. You can restore a deleted image using the undelete [filename] command.
Note: The eighth time you delete a particular file, the file is permanently deleted, and the undelete [filename] command no longer works for that filename.
The following sections discuss these scenarios:
Without a valid Cisco IOS Software image in Flash, you have four different options:
Booting from a TFTP server. This allows you to boot your router, but does not install a valid Cisco IOS Software image in Flash.
Downloading the image through the console port without Xmodem.
If you have booted from a TFTP server, your router should now be operational, even though you do not have a Cisco IOS Software image in Flash.
Note: If your router is rebooted without being connected to the TFTP server, you will end up in TinyROM again.
If you have downloaded an image, you should now have a valid Cisco IOS Software image in Flash, but you still have to boot it. To do so, follow the procedure in the Valid Cisco IOS Software Image in Flash section.
With a valid Cisco IOS Software image in Flash, all you need to do is, set the variables boot-action, file-name, and ios-conf to their correct values like this:
boot# set boot-action=? ----------------------------------------------------------------- set boot-action ={flash|tftp|none} Default boot action to take on power up: flash => run file-name from flash. tftp => tftp file-name (script or image) into RAM, then run it. none => enter CLI and wait for commands from user ----------------------------------------------------------------- boot# set boot-action=flash boot# set file-name=c800-y6-mw.121-5 !--- Or, whatever is your valid Cisco IOS Software image filename. boot# set ios-conf=0x2102
Save the new values, and then boot the router using the boot command:
boot# save save: succeeded (0 seconds). boot# boot# boot Booting "c800-y6-mw.121-5" ..., Restricted Rights Legend Use, duplication, or disclosure by the Government is subject to restrictions as set forth in subparagraph (c) of the Commercial Computer Software - Restricted Rights clause at FAR sec. 52.227-19 and subparagraph (c) (1) (ii) of the Rights in Technical Data and Computer Software clause at DFARS sec. 252.227-7013. cisco Systems, Inc. 170 West Tasman Drive San Jose, California 95134-1706
Revision | Publish Date | Comments |
---|---|---|
1.0 |
18-Dec-2007 |
Initial Release |