You can define the interface that all IPSec packets will be sourced from with:
crypto map local-address Loopback0
or whatever other interface you want to use. The crypto map still needs to be applied on the OUTGOING interface, don't change that, it just means the packets will be sourced from that specific interface address. Also, the other router then has to peer to this Loopback0 address.
For the tunnel to come up the router has to see traffic that matches the access-list. Additionally, the access-list MUST be the exact opposite of the one defined on the peer router.
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...