Password Recovery Cisco 2500

Verify the Configuration Register Value

The first thing that needs to be investigated is why the router is booting up in ROMmon mode (indicated by the "rommon # >" or ">" prompt). Determine whether the cause is due to the change of the configuration register value, or a corrupted Cisco IOS software image.

If the router has a valid Cisco IOS software image, then simply changing the configuration value register to 0x2102 will recover the router. The procedure for this is explained below.

1. If the ROMmon prompt is ">", type the following at the ROMmon prompt:

   >o/r 0x2102      
   >i
   System Bootstrap, Version 11.0(10c)XB2, RELEASE SOFTWARE
   Copyright (c) 1986-2003 by cisco Systems
   2500 processor with 16384 Kbytes of main memory
   
   F3: 10021772+224116+562960 at 0x3000060
   
   Restricted Rights Legend
   
   Use, duplication,............................
   

2. If the ROMmon prompt is "rommon #>", type the following at the prompt:

   rommon 1> confreg 0x2102
   

   You must reset or power cycle the router for the new configuration to take effect:

   rommon 2> reset
   System Bootstrap, Version 12.0(6r)T3, RELEASE SOFTWARE (fc1)
   Copyright (c) 1999 by cisco Systems, Inc.
   UBR924 platform with 16384 Kbytes of main memory.......................

   If the router boots up successfully, then the cause was a configuration register value issue.

If the router boots up in ROMmon again, proceed to Download Cisco IOS Image Using the Boot Image from a Trivial File Transfer Protocol (TFTP) Server.