User manual

25: Dynamic Multipoint Virtual Private Network (DMVPN)
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25 Dynamic Multipoint Virtual Private Network (DMVPN)
Dynamic Multipoint Virtual Private Network (DMVPN) is a scalable method of
creating VPN IPSec Networks. DMVPN is a suite of three protocols: NHRP, mGRE
and IPSec, used to dynamically create VPN tunnels between different endpoints
in the network without having to pre-configure each device with VPN details of
the rest of endpoints in the network.
25.1 The advantage of using DMVPN
• Using DMVPN eliminates the need of IPSec configuration to the physical
interface. This reduces the number of lines of configuration required for a
VPN development. For example, for a 1000-site deployment, DMVPN
reduces the configuration effort at the HUB from 3900 lines to 13.
• Adding new peers (spokes) to the VPN requires no changes at the HUB.
• Better scalability of the network.
• Dynamic IP addresses can be used at the peers’ site.
• Spokes can be connected in private or public network.
• NHRP NAT extension allows spoke-to-spoke tunnels to be built, even if
one or more spokes is behind a Network Address Translation (NAT)
device.
• New HUBs can be added to the network to improve the performances and
reliability.
• Ability to carry multicast and main routing protocols traffic (RIP, OSPF,
BGP).
• DMVPN can be deployed using Activator, the Virtual Access automated
provisioning system.
• Simplifies branch communications by enabling direct branch to branch
connectivity.
• Simplifies configuration on the spoke routers. The same IPSec template
configuration is used to create spoke-to-hub and spoke-to-spoke VPN
IPSec tunnel.
• Improves business resiliency by preventing disruption of business-critical
applications and services by incorporating routing with standards-based
IPsec technology.
25.2 DMVPN scenarios
Scenario 1: Spoke1, Spoke2 and a hub are in the same public or private
network
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© Virtual Access 2015
GW1000 Series User Manual
Issue: 2.4 Page 163 of 255