Just to take this concept a little further. I have a client whose Internet-facing serial interface is configured with "ip unnumbered". In addition, they are running NAT (or rather PAT) overload. Furthermore, some internal hosts that need to be accessed from the Internet are configured for static NAT. The client has a requirement to configure IPSec VPN between this router and a remote site. Usually NAT takes place before IPSec but to avoid this I could configure some policy-routing to insure that the packets from the local private network destined for the remote private network undergo IPsec encryption. However, my problem is - what source address will the IPSec encrypted packets have? In other words, suppose that in the example at
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...