Might be a bit easier to mirror the port that the ASA is on, at the switch level, and then use etherreal. There would be no configuration changes, etc. that you would need to do to the firewall. It would all be at the switch level. If your switch is unmanaged, you could a hub between the switch and the firewall, and then mirror by default on that.
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...