A router uses it's processor to encrypt/decrypt packets which could be detrimental. You can purchase an AIM card which offloads that into hardware. The ASA already has that. Either will work just fine. I usually decide but what else the device will have to do (ie mcast, advanced routing, netflow).
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...
[toc:faq]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 and UDP are I...