Start by doing a 'show version'. The look under the 'Licensed Features' section. The actual features you have enabled will depend on the bundle you have. For example, the Restricted bundle has 3 interfaces, the others have 6. In addition, the Restricted bundle does not support failover. The following document has a list of the differences:
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...