Here are the steps to reset the forgotten password from the Cisco ASA’s without losing the running configuration. below is the screenshot of the physical Cisco ASA and I have pointed out the console port – you will need to be physical there or have out of band access to the Cisco Console port
Once you have access to the firewall – you will need to reboot the firewall by powering off and on and you will see the following screen
Once the firewall is rebooting then you will need to hit the escape key to get into the “rommon mode”
- Hit the Escape key during the reboot
- Note that boot was interrupted and it will take you to “rommon mode”
Once you are in the “rommom” mode then you will need to type “confreg”
Hit enter and make a note of the configuration register value
You will be prompted to enter values and below is the screenshot with all the values that you will need to enter
Now since we have changed the configuration value when we boot the firewall it will bypass the running configuration
Issue the boot command to boot the firewall
Once the firewall reboots then enter “enable” to go to the privilege mode
Now copy the running configuration with the startup config
Make sure you add the username and password before the reboot
Now you will need to change the register value that you noted and you should be good and will be able to login in with the new password