Hi .. I am not too sure what do you mean by 'redundant pair' .. it you are talking about failover then I am assuming you are using Active / Standby model. In this case you don't need to monitor the standby as it does not do much unless it takes over the active role. Now tehre is a good document that you could use to monitor the status of your Active PIX. Please see the below link
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...