Cisco 2811 log in problem

[Ihabmoussa]

I am encountering an issue with logging in to a Cisco device using the default credentials ("cisco" for both the username and password). The device is a Cisco router model 2811 with Cisco IOS Software version 12.4(15)T12. Upon attempting to log in, I receive repeated "Login invalid" messages.
However, I was able to log in first time but then I could not.

Configuration Information:

• Device Model: Cisco 2811 (revision 49.46)

• Cisco IOS Software: C2800NM-SPSERVICESK9-M, Version 12.4(15)T12, RELEASE SOFTWARE (fc3)

• Installed Feature: Cisco Configuration Professional (Cisco CP)
• Privilege Level for Default Credentials: 15.
  
  
  I also still have the message after logging in:
  
  

  
  -----------------------------------------------------------------------
  Cisco Configuration Professional (Cisco CP) is installed on this device.
  This feature requires the one-time use of the username "cisco" with the
  password "cisco". These default credentials have a privilege level of 15.

  YOU MUST USE CISCO CP or the CISCO IOS CLI TO CHANGE THESE PUBLICLY-KNOWN
  CREDENTIALS

  Here are the Cisco IOS commands.

  username <myuser> privilege 15 secret 0 <mypassword>
  no username cisco
  
  Replace <myuser> and <mypassword> with the username and password you want
  to use.

  IF YOU DO NOT CHANGE THE PUBLICLY-KNOWN CREDENTIALS, YOU WILL NOT BE ABLE
  TO LOG INTO THE DEVICE AGAIN AFTER YOU HAVE LOGGED OFF.

  For more information about Cisco CP please follow the instructions in the
  QUICK START GUIDE for your router or go to http://www.cisco.com/go/ciscocp
  -----------------------------------------------------------------------

[pieterh]

what commands did you use after the first succesful login ?
IF YOU DO NOT CHANGE THE PUBLICLY-KNOWN CREDENTIALS, YOU WILL NOT BE ABLE
TO LOG INTO THE DEVICE AGAIN AFTER YOU HAVE LOGGED OFF.

this means if you did not configure a new username or changed the default password, the default account cisco will be invalid
-> you need to initiate password recovery, to reset the device to factory default and start over again

[Ihabmoussa]

I just copied the software version to usb flash.
I did not notice the message at first and logged off.
How could i recover the password?

[pieterh · Accepted solution]

Password recovery - Cisco Community

1. Remove the flash card and boot the device. It will boot into ROMMON.

2. Set the config register to 0x2142.
   
   confreg 0x2142

3. Put the flash card back on and boot the router.
4. When the router reboots it will load the old configuration with the new password.
5. Save the password so that it will be persistent during reboots, type copy run start.
6. Reboot the router by typing reload at the enable prompt.