Posts Tagged ‘password recovery’

Cisco 3750 Password Recovery

Monday, June 1st, 2009


This password recovery method also applies to at least the:
Cisco 2950, Cisco 2960, Cico 3550, Cisco 3560 and Cisco 3750 series.
The only difference will be for how long you will hold the mode button,
from my experience just try to hold it longer if it doesn’t work.
(It should be around 15 seconds for the 3750.)

Connect the PC to the console port
Settings:

  • 9600 bits
  • 8 data bits
  • ‘none’ parity
  • 1 stop bit

If the switch is powered on, power it off and press and hold the mode button while you power on the switch again. Hold it for about 15 seconds until the SYS led is solid green, then release it.

The switch should then give you this prompt

switch:

To initialize the flash file system, run the command

switch: flash_init

The switch will now print a bunch of messages about the flash memory, hopefully one of them will be ‘done initializing flash’.
The next command is load_helper to load any helper images required by boot.

You can now list the contents of your flash by running dir flash:
There should be a file named ‘config.text’, you can rename this file

switch: rename flash:config.text flash:oldconfig.backup

To further boot the switch run the boot command, this will start the boot you are used to. When the switch is booted up, you will realize that the configuration is gone.. But you are enabled on the switch now.

To recover the old configuration:

Switch#rename flash:oldconfig.backup flash:config.text

And now to replace the running configuration with the backup

Switch#copy flash:config.text running-config
Destination filename [running-config]?

Press enter, and you will have your old switch configuration back and you are enabled.
Just remember to change your password now! 😀