2811 router sits at ROMMON prompt after power outage.

Unanswered Question
Nov 9th, 2008

When the 2811 router is turned OFF and ON it does auto boot correctly every time. No problem there.

But when there is a power failure / power recovery the router goes and sits at ROMMON prompt.

I have to find out the config-reg values etc. but I can't believe problem to be with config-reg because customer tells me that it boots everytime fine when router power is turned OFF and then ON. The problem is just after power outage. I can't see the difference.

Customer said that he found a Field Notice (I am still searching for that Field Notice) where the solution to this problem is to upgrade the ROMMON which he has done but he still has the same problem even after upgrading teh ROMMON.

I have this problem too.
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Richard Burts Sun, 11/09/2008 - 16:54


The symptoms as described are quite strange. I am not sure why the recovery from a power outage would be any different from a power off/power on - unless perhaps it is the amount of time that the router was powered down.

I would suggest that the first thing to do is to very the setting of the config register



cisco24x7 Sun, 11/09/2008 - 18:42

The issue has to do with the firmware in the

ROMMON. I ran into the exact same issue you

described on the Cisco 2851 router running IOS

code c2800nm-advipservicesk9-mz.124-16.bin.

You need to upgrade the firmware code to

C2800NM_RM2.srec.124-13r.T5. That will fix

your problem.

Easy right?

glen.grant Sun, 11/09/2008 - 17:02

You probably have hit it on the head about the rommon . I think we have seen that once or twice in those models but we have dial backup in most places so we just issue a boot command and it loads. I think it happens when you get a quick power hit where it doesn't go all the way down properly and then the power comes back on quickly. It may be field notice 62127 , which says

# The router may fail to auto-boot its flash image:

Note: This type of failure as shown in 1.a. and 1.b has been seen and documented:



Readonly ROMMON initialized

boot: cannot open "flash:"

boot: cannot determine first executable file name on device "flash:"

cxxxx processor with 524288 Kbytes of main memory Main memory is configured

to 64 bit mode with ECC enabled

Readonly ROMMON initialized

rommon 1 >

The above has been seen on a Cisco 3800 router.


System Bootstrap, Version 12.3(8r)T, RELEASE SOFTWARE (fc1) Technical

Support: http://www.cisco.com/techsupport Copyright (c) 2004 by Cisco Systems,Inc.

PLD version 0x10

GIO ASIC version 0x127

At this point, the system cannot execute from boot flash with the affected Compact Flash when the software enables the quick switches.

The above has been seen on a Cisco 2801 router.

# A router reboot may be triggered from a momentary system power resource overload. This reboot may or may not fail due to the symptom described in scenario #1 directly above.

# System accesses to compact flash for certain operations like CLI compact flash queries, TFTP download, or IOS VLAN database storage updates may not be complete. Interruption of services requiring compact flash will result as if compact flash were removed from the system.

Following are two failure messages one can get from console output with a failed compact flash:

astanislaus Sun, 11/09/2008 - 18:49

I have the correct Bootstrap Version:


------------------ show flash: all ------------------

-#- --length-- -----date/time------ path

1 44909204 May 15 2008 10:55:32 +10:00 c2800nm-entservicesk9-mz.124-11.XW2.bin

2 39682544 May 15 2008 11:04:18 +10:00 c2800nm-entservicesk9-mz.124-11.XJ4.bin

3 1623191 Oct 22 2008 07:14:18 +10:00 C2800NM_RM2.srec.124-13r.T6


------------------ show version ------------------

Cisco IOS Software, 2800 Software (C2800NM-ENTSERVICESK9-M), Version 12.4(11)XW2, RELEASE SOFTWARE (fc1)

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 1986-2007 by Cisco Systems, Inc.

Compiled Mon 02-Jul-07 18:13 by prod_rel_team

ROM: System Bootstrap, Version 12.4(13r)T6, RELEASE SOFTWARE (fc1)

twb02rtr01-2811 uptime is 6 days, 3 hours, 53 minutes

System returned to ROM by power-on

System restarted at 07:15:59 AEST Tue Nov 4 2008

System image file is "flash:c2800nm-entservicesk9-mz.124-11.XW2.bin"

This product contains cryptographic features and is subject to United

States and local country laws governing import, export, transfer and

use. Delivery of Cisco cryptographic products does not imply

third-party authority to import, export, distribute or use encryption.

Importers, exporters, distributors and users are responsible for

compliance with U.S. and local country laws. By using this product you

agree to comply with applicable laws and regulations. If you are unable

to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:


If you require further assistance please contact us by sending email to

[email protected].

Cisco 2811 (revision 53.51) with 251904K/10240K bytes of memory.

Processor board ID FHK0924F21R

2 FastEthernet interfaces

1 HSSI interface

DRAM configuration is 64 bits wide with parity enabled.

239K bytes of non-volatile configuration memory.

125440K bytes of ATA CompactFlash (Read/Write)

Configuration register is 0x2102


Partial Config:



boot system flash:c2800nm-entservicesk9-mz.124-11.XW2.bin

boot system flash:c2800nm-entservicesk9-mz.124-11.Xj4.bin



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