If you find yourself unable to load a new software image onto your ASA via all standard methods, then you can load a new image from rommon (ROM monitor mode) using TFTP. To enter into rommon:
- Connect a console cable to the console port of the ASA
- Power cycle or power on the ASA
- As the appliance is starting, press the Escape key to enter rommon
To load an image onto your ASA via rommon:
- Connect Eth0/0 to your network
- Assign IP address config to your ASA:
rommon #1> ADDRESS=192.168.0.201
rommon #2> SERVER=192.168.0.21
rommon #3> GATEWAY=192.168.0.1
rommon #4> IMAGE=asa911-k8.bin
rommon #5> PORT=Ethernet0/0 - Then issue the tftp command
rommon #6> tftp - The ASA will then transfer the image and boot from it
- After the firewall boots, login and check (show version)