I know when we started upgrading our customers PIX's to a failover configuration, our Cisco rep said they must be identical hardware so we always sell two and give them a respectible trade-in on the old PIX. I know there could be problems with different hardware
While failover "may" work between two unlike PIX's, it is not tested, recommended or supported by Cisco. There may be programs through your reseller channels to help you migrate to a failover PIX configuration that provides greatest reliability and performance for your specific needs.
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...