FreeSWAN does work for a site-to-site connection, but it doesn't do anything useful for a scalable number of remote access users. The Linux client runs on Linux only (Intel). You could use L2TP/IPsec if there was such a client, but we haven't tested to ensure compatibility, I am not sure of any particular clients to be testing with.
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...