I'm running into the same issue with a recent setup on an ASA 5505 running 8.0(5). I'm seeing the same behavior with a handshake, repeated push from the client and then a reset from client. Trying to initiate another rdp connection shows syns from client but no ack from server. clearing the arp cache helps temporarily but the problem returns after a short time.
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...