I have the exact same problem and would love to get an answer. I have tried the 3.0.6 client, and the 3.1.1 client. Most of the time the connection goes through, but sometimes I get stuck at "securing communication channel". Even when authentication works, it can often take a minute or more for it to get by the "securing communication channel" part. I also have a PIX 515 running 6.0.1 IOS. This happens from a variety of operating sysytems (windows 9x, NT, 2k).
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...