Thanks for your reply. VPNs are not my strong point so I am learning as I go here!
Correct me if I am wrong here as I understand it the router needs to see traffic from a network going to a specified network in order for that to be encrypted and sent via the tunnel.
Therefore do I need to tell the router that the interface for the VPN is e.g. fa0/0 and the source for the traffic is the same interface. I do not quite understand how I can tell the router the external IP address for encryption.
My misunderstanding is that the fa0/0 is not a public facing interface it is sitting on the LAN behind another router. I have attached a network diagram.
Any client on the 192.168.2.x range that wishes to communicate to the 192.168.1.x range will forward the packets to the 1841 (its default gateway), my understanding is that the router will then see those packets destined for that network and encrypt them and forward them to an Internet routable address via its default gateway to the Internet to the other VPN peer.
I appologise for my lack of understanding and apprcaite your patience and help.
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...