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1841 router enter ROMMON>

Please this is very urgent. I have a 1841 router that enter ROMMON mode each time I boot. Please tell the troubleshooting step to revive it. VERY URGENT.

Hall of Fame Super Bronze

Re: 1841 router enter ROMMON>

Your IOS may be missing or you have an incorrect config-register.

This document will explain how to identify if your IOS is missing or fix the config-register issue:




Community Member

Re: 1841 router enter ROMMON>

Dont think its any of the two, cos it was working before it stop, wit 0X2102. i use to use some steos, but forgot.

Hall of Fame Super Bronze

Re: 1841 router enter ROMMON>

What happens if you type boot on rommon? Do you get an error?

Community Member

Re: 1841 router enter ROMMON>


i had similar incident with my 871 router, i discovered it was a case of corrupted ios. This is how to resolved it:

First download the required ios u need to a tftp server.

Make sure the tftp server has an active connection to the router, preferably have a direct connection between the tftp server and the router interface so that they will be on the same subnet.

use tftpdnld command in romon.

when the router boots to the romon environment, use the 'set' command to view the Rommon environment variables.

rommon 3 > set

PS1=rommon ! >






the variables to set for tftpdnld are

usage: tftpdnld [-ur]

Use this command for disaster recovery only to recover an image via TFTP.

Monitor variables are used to set up parameters for the transfer.

(Syntax: "VARIABLE_NAME=value" and use "set" to show current variables.)

"ctrl-c" or "break" stops the transfer before flash erase begins.

The following variables are REQUIRED to be set for tftpdnld:

IP_ADDRESS: The IP address for this unit

IP_SUBNET_MASK: The subnet mask for this unit

DEFAULT_GATEWAY: The default gateway for this unit

TFTP_SERVER: The IP address of the server to fetch from

TFTP_FILE: The filename to fetch

The following variables are OPTIONAL:

TFTP_VERBOSE: Print setting. 0=quiet, 1=progress(default), 2=verbose

TFTP_RETRY_COUNT: Retry count for ARP and TFTP (default=7)

TFTP_TIMEOUT: Overall timeout of operation in seconds (default=7200)

TFTP_CHECKSUM: Perform checksum test on image, 0=no, 1=yes (default=1)

Command line options:

-r: do not write flash, load to DRAM only and launch image

-u: upgrade the rommon, system will reboot once upgrade is complete

rommon 14 >

Look at an example i got from a reference i was refered to:


rommon 16 > IP_ADDRESS=

rommon 17 > IP_SUBNET_MASK=

rommon 18 > DEFAULT_GATEWAY=

rommon 19 > TFTP_SERVER=

rommon 20 > TFTP_FILE=c2600-is-mz.113-2.0.3.Q

rommon 21 > tftpdnld





TFTP_FILE: c2600-is-mz.113-2.0.3.Q

Invoke this command for disaster recovery only.

WARNING: all existing data in all partitions on flash will be lost!

Do you wish to continue? y/n: [n]: y

Receiving c2600-is-mz.113-2.0.3.Q from !!!!!.!!!!!!!!!!!!!!!!!!!.!!

File reception completed.

Copying file c2600-is-mz.113-2.0.3.Q to flash.

Erasing flash at 0x607c0000

hope this helps.


Hall of Fame Super Blue

Re: 1841 router enter ROMMON>

IOS could be missing or corrupted.

How to Download a Software Image to a Cisco 2600 via TFTP Using the tftpdnld ROMMON Command

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