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Router loses configuration due to wrong config-register value

Core Issue

The configuration register is set to ignore startup configuration.


Issue the config-register command from global configuration mode, and set the configuration register to 0x2102.

For more information, refer to Why Does My Router Lose Its Configuration During Reboot?

If the router has a valid Cisco IOS  Software image, then changing the configuration value register to 0x2102 recovers the router.

If the ROMmon prompt is ">", type the following  at the ROM Monitior (ROMmon) prompt:

  >o/r 0x2102 

  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,............................ 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.

For more information, refer to these documents:

Version history
Revision #:
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Last update:
‎06-22-2009 03:37 PM
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