Factory Reset Firepower 4100 & 9300

I got my hands on some Cisco Firepower 4100 units and after playing around with them I wanted to reset them to factory settings, essentially erase the “startup-config” on the FXOS. The Firepower units act a little differently than your normal Cisco IOS or ASA and you can’t just erase startup-config and reload the device, that would be too easy.

(Edit: 7-21-17) After Gabriele made this comment - “connect local-mgmt” and then “erase configuration” it looks like you can. Thanks Gabriele

You also can follow the  password recovery on this post which will also erases the configuration. You have to be physically at the device with a console cable, plug into the console port to begin:

• Power off the system, and then power it back on
• While the system is booting, you have go into ROMMON mode to do that press ESC or CTRL+L. You’ll see a message confirming that you are going to ROMMON

!!  Rommon image verified successfully  !! 
 
Cisco System ROMMON, Version 1.0.10, RELEASE SOFTWARE 
 
Copyright (c) 1994-2015  by Cisco Systems, Inc. 
 
Compiled Mon 11/30/2015 15:23:18.60 by builder 
 
Current image running: Boot ROM0 
 
Last reset cause: PowerCycleRequest 
 
DIMM Slot 0 : Present 
 
DIMM Slot 1 : Present 
 
No USB drive !! 
 
BIOS has been locked !! 
 
Platform FPR-4110-SUP with 8192 Mbytes of main memory

Make note of the kickstart and FXOS system image as you need these names to be able to boot to the correct image. In this example under ROMMON the following appeared on-screen

boot bootflash:/installables/switch/fxos-k9-kickstart.5.0.3.N2.3.14.69.SPA bootflash:/installables/switch/fxos-k9-system.5.0.3.N2.3.14.69.SPA

• Load the kickstart image

rommon 1 > boot bootflash:/installables/switch/fxos-k9-kickstart.5.0.3.N2.3.14.69.SPA 
 
  !!   Kickstart Image verified successfully   !!

• When kickstart loads you’ll be at the switch(boot)# prompt, enter configuration mode.

switch(boot)#
switch(boot)# config t
Enter configuration commands, one per line. End with CNTL/Z.

• Under the configuration mode, type admin-password erase, this will erase everything and bring the system back to factory defaults.

switch(boot)(config)# admin-password erase
Your password and configuration will be erased!
Do you want to continue? (y/n)  [n] y
switch(boot)(config)# exit

• Load the system image to startup the FXOS, once the image has been loaded you’ll be prompted to enter the setup wizard.

switch(boot)# load bootflash:/installables/switch/fxos-k9-system.5.0.3.N2.3.14.69.SPA
Uncompressing system image: bootflash:/installables/switch/fxos-k9-system.5.0.3.N2.3.14.69.SPA
 
You have chosen to setup a new Security Appliance. Continue? (y/n):

I hope this information is helpful, the information I was referencing is located here: Password Recovery Procedure For Firepower 9300/4100 Series Appliances