There is a range of benefits of using DMVPN over a permanent VPN, or in the case of DMVPN vs MPLS networks. The following are some of the most commonly cited benefits:
Offers superior internet speed and reliability performance, in general.
Reduces the cost of secure communications and connections between branches by integrating VPN with communication practices.
Allows for easier branch-to-branch communications and connections through a centralized system.
Reduces the likelihood of downtime by securing routing with IPsec technology.
DMVPN Phase 1 uses HUB-and-spoke tunnel deployment. The tunnels through which inter-branch connections are made are only built through the central DMVPN hub and the individual spokes, working much like a traditional VPN system.
DMPVN Phase 2 uses spoke-to-spoke tunnel deployment, meaning that data doesn’t have to travel to a central hub first, so long as there are specific routes in place for the spoke subnets.
DMPVN Phase 3 allows for spoke-to-spoke tunnel deployment, but without the specific pre-made routes in place, but rather uses NHRP traffic indication messages from the hub to secure those routes on the fly.
Hub and Spoke Network Architecture
As mentioned, the Hub and Spoke Network Architecture is a way to efficiently manage the endpoints that are being secured. There are three different phases, each of them suitable for different configurations. However, in general, the hub is used to configure the protocols by which the connections are secured, and these protocols are then applied to the spokes (or endpoints) of the network. This system can be centralized to ensure that allow spoke-to-spoke tunnels first go through the hub, or can be decentralized to cut the hub out entirely.
Dynamic Multiple VPN (or DMVPN) is a complex topic, but it’s a security configuration that could allow businesses that use a wide range of remote endpoints (or flexible endpoints that move location often) to make sure they can keep the security of their network in place, which making sure it’s flexible and not prohibitive in costs.