1. I am not as familiar with the IPSec implementation in the router IOS, but yes I believe the router can do DES and 3DES at the same time. You just need to make sure you have the recommended amount of memory to support 3DES.
2. You should be able to set up two policies, one using DES and one using 3DES. When the client connects, it and the router will negotiate what type of encryption will be used in the tunnel. If the client says it can only do DES, then the tunnel will be set up with DES.
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...