how to reset cisco router 1841 password

Answered Question
Sep 17th, 2012

Hi

Hava cisco router 1841 forgot user name and password and need to reset it to its factory setting pls help

tried boot while holding ctrl and break get into rommon1>

rommon1>confreg 0*2142

rommon1>reset

still shows rommon 3>

pls help,it ask user name and password and cant remember both

thx

J

I have this problem too.
0 votes
Correct Answer by amuthaia about 1 year 6 months ago

Hi Joseph,

Please execute the below command on the rommon prompt again,

rommon>confreg 0x2142 (not confreg 0*2142)

rommon>reset

Please see the regular process to reset the password on 1841 Router below,

  • Connect the console cable to Router 1841
  • Use the power switch in order to turn off the router, and then turn the router back on
  • Press Break on the terminal keyboard within 60 seconds of power up in order to put the router into ROMMON
  • Type confreg 0x2142 at the rommon 1> prompt in order to boot from Flash

          This step bypasses the startup configuration where the passwords are stored

  • Type reset at the rommon 2> prompt.

          The router reboots, but ignores the saved configuration.

  • Type no after each setup question, or press Ctrl-C in order to skip the initial setup procedure.
  • Type enable at the Router> prompt.
  • You are in enable mode and should see the Router# prompt.
  • Type copy startup-config running-config in order to copy the nonvolatile RAM (NVRAM) into memory.

Important:

Do not type copy running-config startup-config or write. These commands erase your startup           configuration.

  • Type configure terminal
  • Type #enable secret <password> in order to change the enable secret password.
  • Type config-register #config-register 0x2102
  • Type write memory or #copy running-config startup-config in order to commit the changes

Refer:

http://www.cisco.com/en/US/products/hw/routers/ps221/products_password_recovery09186a0080094773.shtml

If you couldnt boot the device after execute the below commands,

rommon>confreg 0x2142

rommon>reset

As Ivan suggested, please try to boot the image from flash or bootflash where you stored the actual IOS image

rommon>boot (Boot the first image in flash memory)

rommon>boot flash:[filename] (Boot the first image or a specified image in flash memory)

rommon>boot <filename> tftpserver (Boot the specified image over the network from the specified TFTP server (hostname or IP address)

example: rommon>boot <image name> 172.16.30.40

If this doesnt work, you can recover the System Image (tftpdnld)

Note: Use the tftpdnld command only for disaster recovery because it can erase all existing data in flash memory before it downloads a new software image to the router.

Before you can enter the tftpdnld command, you must set the ROM monitor environment variables.

Prerequisites

Connect the TFTP server to a fixed network port on your router.

rommon 16 > IP_ADDRESS=171.68.171.0

rommon 17 > IP_SUBNET_MASK=255.255.254.0

rommon 18 > DEFAULT_GATEWAY=171.68.170.3

rommon 19 > TFTP_SERVER=171.69.1.129

rommon 20 > TFTP_FILE=c2600-i-mz.120-7.T.bin

rommon 21 > tftpdnld

After the tftpdnld procedure is complete, the router goes back to a ROMmon prompt.

Issue the confreg 0x2102 command and reset. If the confreg 0x2102 command is not issued, the router boots to ROMmon mode after the reset

rommon1>confreg 0x2102

rommon2>reset

Refer:

http://www.cisco.com/en/US/docs/routers/access/1800/1841/software/configuration/guide/b_rommon.html

https://supportforums.cisco.com/docs/DOC-2340

Regards,

Aru

Correct Answer by rajs2 about 1 year 6 months ago

You need to boot the router after that.

Type boot from the rommon if you have set the boot variable correctly

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Average Rating: 5 (2 ratings)
Correct Answer
rajs2 Mon, 09/17/2012 - 10:16

You need to boot the router after that.

Type boot from the rommon if you have set the boot variable correctly

Ivan Shirshin Mon, 09/17/2012 - 10:36

Hi,

Since the router is in ROMMON after reset, it means the autoboot failed. Likely router cannot find the image.

Do you know where it is located? Use "dev" command in ROMMON mode to see file systems, then "dir ..." to list the files in each of them and boot with correct image manually using "boot ...".

     dev   

     dir :

     boot :

PS: please capture console logs from the terminal when working this steps. In case of some issues it will help to find the problem.

Kind Regards,
Ivan Shirshin

**Please grade this post if you find it useful.

malai.joseph Mon, 09/17/2012 - 23:05

Hi Aru,

this is what happened,what next?

rommon 2 > dev

Devices in device table:

        id  name

    flash:  external compact flash

bootflash:  boot flash

    eprom:  eprom

j

rajs2 Mon, 09/17/2012 - 23:42

Please get the following output

rommon 1 > ?

rajs2 Mon, 09/17/2012 - 23:55

try

dir flash:

if that doesn't work please get help output

rommon 1 > ?

amuthaia Mon, 09/17/2012 - 10:42

Hi Joseph,

As Ivan said, it failed to auto boot after you gave reset from rommon prompt. I would like to confirm you one more thing, did you try to execute * or x

I mean, 0*2142 or 0x2142

Regards,

Aru

Correct Answer
amuthaia Tue, 09/18/2012 - 02:41

Hi Joseph,

Please execute the below command on the rommon prompt again,

rommon>confreg 0x2142 (not confreg 0*2142)

rommon>reset

Please see the regular process to reset the password on 1841 Router below,

  • Connect the console cable to Router 1841
  • Use the power switch in order to turn off the router, and then turn the router back on
  • Press Break on the terminal keyboard within 60 seconds of power up in order to put the router into ROMMON
  • Type confreg 0x2142 at the rommon 1> prompt in order to boot from Flash

          This step bypasses the startup configuration where the passwords are stored

  • Type reset at the rommon 2> prompt.

          The router reboots, but ignores the saved configuration.

  • Type no after each setup question, or press Ctrl-C in order to skip the initial setup procedure.
  • Type enable at the Router> prompt.
  • You are in enable mode and should see the Router# prompt.
  • Type copy startup-config running-config in order to copy the nonvolatile RAM (NVRAM) into memory.

Important:

Do not type copy running-config startup-config or write. These commands erase your startup           configuration.

  • Type configure terminal
  • Type #enable secret <password> in order to change the enable secret password.
  • Type config-register #config-register 0x2102
  • Type write memory or #copy running-config startup-config in order to commit the changes

Refer:

http://www.cisco.com/en/US/products/hw/routers/ps221/products_password_recovery09186a0080094773.shtml

If you couldnt boot the device after execute the below commands,

rommon>confreg 0x2142

rommon>reset

As Ivan suggested, please try to boot the image from flash or bootflash where you stored the actual IOS image

rommon>boot (Boot the first image in flash memory)

rommon>boot flash:[filename] (Boot the first image or a specified image in flash memory)

rommon>boot <filename> tftpserver (Boot the specified image over the network from the specified TFTP server (hostname or IP address)

example: rommon>boot <image name> 172.16.30.40

If this doesnt work, you can recover the System Image (tftpdnld)

Note: Use the tftpdnld command only for disaster recovery because it can erase all existing data in flash memory before it downloads a new software image to the router.

Before you can enter the tftpdnld command, you must set the ROM monitor environment variables.

Prerequisites

Connect the TFTP server to a fixed network port on your router.

rommon 16 > IP_ADDRESS=171.68.171.0

rommon 17 > IP_SUBNET_MASK=255.255.254.0

rommon 18 > DEFAULT_GATEWAY=171.68.170.3

rommon 19 > TFTP_SERVER=171.69.1.129

rommon 20 > TFTP_FILE=c2600-i-mz.120-7.T.bin

rommon 21 > tftpdnld

After the tftpdnld procedure is complete, the router goes back to a ROMmon prompt.

Issue the confreg 0x2102 command and reset. If the confreg 0x2102 command is not issued, the router boots to ROMmon mode after the reset

rommon1>confreg 0x2102

rommon2>reset

Refer:

http://www.cisco.com/en/US/docs/routers/access/1800/1841/software/configuration/guide/b_rommon.html

https://supportforums.cisco.com/docs/DOC-2340

Regards,

Aru

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