In my Cisco routers I have multiple boot statements in the event that one of the images fails to load or is accidently deleted. For example a router may have a config such as:
boot system flash disk0:PREFERED_IMAGE.bin
boot system flash disk0:OLD_IMAGE.bin
The router tries to boot PREFERED_IMAGE.bin first since it is first in the order.
Can I configure an ASA similarly? or does multiple boot statements in an ASA cause issues?
boot system disk0:/PREFERED_IMAGE.bin
boot system disk0:/OLD_IMAGE.bin
asdm system disk0:/PREFERED_ASDM.bin
asdm system disk0:/OLD_ASDM.bin
Best Answer
Yes you can have up to four boot statements. One of those four can be a tftp target. They work just as you have outlined in the Question. Lacking a boot statement, or if all boot statement targets fail, the ASA will try any image it finds on the internal flash. Then the same for the external flash.
You can only have one asdm statement. Setting another will simply remove the existing setting.