I am upgrading ASA (in failover) from version 8.0 to 8.2 which i believe is next minor version for 8.0 (as 8.1 is used for ASA 5580) so please let me know if Zero downtime is possible for the same as per the below link or not .I believe the same is possible .
To ensure that your configuration updates correctly, you must upgrade to each major release in turn. Therefore, to upgrade from Version 7.0 to Version 8.2, first upgrade from 7.0 to 7.1, then from 7.1 to 7.2, and finally from Version 7.2 to Version 8.2 (8.1 was only available on the ASA 5580).
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...