Catalyst 3750

[jonmeeks0429]

I'm trying to find out how to completly default 2 3750 switches.  They are 2 that we are taking over and no one can give us any information on them. I have no login in or password.  I also have no software that is needed cause i dont know which one to use. I tried Cisco Network assistant but i still can not get in.  Any help would be great.  Thanks Jon Meeks

[pdub206]

Hi Jon,

This happens on occasion and I have had it happen to me as well.  The easiest solution is to enter the break sequence, using a console connection while the switch is powering up.  This is usually ctrl+shift+6, but it can also be the actual pause/break key on your keyboard in some platforms if I recall correctly.

Once you have done this, the switch will boot into what is called ROMMON mode, and allow you to change the configuration register code to bypass the startup-config file where the username/password information is located.  You can find all the confreg codes in the link below:

http://www.cisco.com/c/en/us/support/docs/routers/10000-series-routers/50421-config-register-use.html

Once you have selected the appropriate confreg code (likely 0x2142), you can boot the device and it will be at the factory default configuration.  You can either then erase the startup-configuration, or perform a 'copy start run' to load the old running-configuration options.  This may be good in case you want to keep the existing configuration, but add a new user with privilege 15 and change the enable secret.

Good luck, and please rate if helpful!

[kravetspd]

Hi!

There are some steps If you have some issues with booting in ROMMON:

1. Plug a console cable to your switch.

2. Power OFF your switch by unplugging power cord.

3. Press "Mode" button on a face of your 3750 while reconnecting the power cord and release the button after LEDs above ports goes off.

4. Look at the console window, you should see "Switch:" prompt. It is a bootloader.

5. Follow recovery procedure  mentioned above.

Best regards!