We are running DMVPN EIGRP topology in our network. The DMVPN hub aggregates all the spoke router networks via the tunnel. ALso the Spoke routers allow internet traffic by using NAT and only private traffic flows through the DMVPN tunnel. The IPSec is up and running fine and EIGRP works good.
Brief configs on Hub and Spoke are as below:
description VPN tunnel
ip address 172.28.1.159 255.255.252.0
ip nhrp authentication xxx
ip nhrp map 172.28.1.1 6x.xx.x.x
ip nhrp network-id 100000
ip nhrp holdtime 360
ip nhrp nhs 172.28.1.1
ip summary-address eigrp 100 10.159.0.0 255.255.0.0 5
For the NAT-Transparency Aware enhancement to work, you must use IPSec transport mode on the transform set. Also, even though NAT-Transparency (IKE and IPSec) can support two peers (IKE and IPSec) being translated to the same IP address (using the User Datagram Protocol [UDP] ports to differentiate them [this would be Peer Address Translation]), this functionality is not supported for DMVPN. All DMVPN spokes must have a unique IP address after they have been NAT translated. They can have the same IP address before they are NAT translated.
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...