Recovering Passwords on Cisco Catalyst Switches

March 2001 · 4 min read

Recovering a lost or forgotten password on a Cisco Catalyst switch can be stressful, especially in production environments. Fortunately, Cisco has built-in mechanisms that let engineers regain access without wiping the device entirely.

Accessing ROMMON Mode

For most Catalyst switches in 2001 (such as 2900XL or 3500XL), the first step is to interrupt the boot sequence by sending a break signal during startup. This brings the device into ROMMON or switch: prompt, depending on the model.

Changing the Configuration Register

Once at the prompt, change the configuration register to bypass the startup configuration:

  switch: flash_init
  switch: load_helper
  switch: rename flash:config.text flash:config.old
  switch: boot
  

After the device boots, enter privileged mode, then copy the old configuration file back and reset the password.

Final Steps

Make sure to restore the original config and reset the configuration register to its default (usually 0x2102) before reloading:

  Switch# copy flash:config.old system:running-config
  Switch# configure terminal
  Switch(config)# enable secret 
  Switch(config)# config-register 0x2102
  Switch# write memory
  Switch# reload
  

Password recovery doesn’t have to be painful — just be prepared and know your hardware platform.

 

Eduardo Wnorowski is a technology consultant focused on network infrastructure. He shares practical insights from the field for engineers working with Cisco technologies.