This is probably more commonly referred to as a site-to-site or LAN-to-LAN VPN. Basically two VPN devices build a tunnel between them, and when traffic from behind one device is sent to traffic behind the other device, that traffic is encrypted between the two, then decrypted at the destination device. Most VPN's that connect sites over the Internet are this type.
The other main type of VPN is a client VPN, where software on a PC is used to build a tunnel to a VPN concentrator of some sort, allowing users on the road to connect into their company's network over a public network.
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...