We are going through these talks now with Cisco and DMVPN has limitations with EIGRP you have to look out for. Look at the SRND from Cisco on DMVPN as it requires a great deal of hardware for a small amount of spokes.
Although the comments on hardware and what it can handle is correct, we ran several design consideration by Cisco RTP and all they will commit to in single-tier design is 800 spokes per head-end device. This is not because of CPU/Throughput/Enrcyption it is purely based on limitation in and around EIGRP neighbors and convergence times.
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...