Incase if you are to shutdown/reboot the Cisco Firepower Threat Defense (FTD) appliance, there are few additional steps to be done. Below is the list of steps.
- SSH directly into the FTD appliance.
- Issue the connect fxos command to access the FXOS CLI.
- Enter Chassis mode using scope chassis 1.
- To reboot the device, issue the command reboot | to shutdown the device, issue the command reboot
After that you can simply exit the FXOS mode and issue shutdown or reboot commands.