Nov 27, 2009

Break or recover the Router Password

  • Turn the power switch off and back on to recycle the power. 
  • Press the Break key or key sequence to put the router into ROM Monitor mode. The break key varies by computer or terminal software. The sequence might be CTRL-D, CTRL-Break or another combination. 
  • At the  > prompt, type 0 to record the current value of the configuration register normally 0x2102, or 0x102.
>o
Configuration register = 0x2102 at last boot
Bit#    Configuration register option settings:
15      Diagnostic mode disabled. 
  • Type o/r 0x2142 to tell the router to boot from flash without loading the configuration in NVRAM at the next reload. 
  • Type i to have the router reboot. The router ignores the configuration in NVRAM.
  • The router runs the setup dialog, Type no or press Ctrl-C to skip the initial setup Dialog
  • Type enable ate the Router> prompt to go to privileged exec mode.
  • Copy the startup configuration to the running configuration by using the configure memory or copy startup-config running-config commands. Do not type configure terminal. If you use the configure terminal command, you overwrite the configuration stored in NVRAM.
  • View the configuration by typing write terminal or show running-config. View the configured line, vty and enable passwords. Any encrypted passwords need to be changed. 
  • Enter the configuration mode by typing configure terminal. Change the line of enable passwords as necessary. 
  • All interfaces are in a shutdown state. Issue the no shutdown command on every interface that is to be used.
  • Type config-register 0x2102 to return the router to normal operation at the next reloads.
  • Exit configuration mode by pressing Ctrl-Z
  • Save your changes by typing write memory or copy running-config startup-config.
  • Reload the router and verify the passwords.

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