The IPSec NAT Transparency feature introduces support for IPSec traffic to travel through NAT or Point Address Translation (PAT) points in the network by addressing many known incompatabilites between NAT and IPSec.
NAT Transparency uses User Datagram Protocol (UDP) port 4500 to encapsulate IPSec packets. By default, PIX drops all inbound connections coming from the outside. You must open this port for NAT Transparency to work.
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...