Happened to me while I tried to upgrade the standby in a active/standby pair.
I ended up going into ROMMON mode and setting an IP on the management interface for the network it was on. I then set the TFTP and Filename parameters and did a TFTP boot of the OS. Once the system was up, you have to re-TFTP over the OS as it is not saved on disk0:
Once you get into ROMMON, do a question mark to get a list of the commands you can set. It will be obvious on what to do.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...