Introduction. In this blog, I aim to go a little deeper into how the different DMVPN phases work and how to properly configure the routing. DMVPN Explained. DMVPN stands for Dynamic Multipoint VPN and it is an effective solution for dynamic secure overlay networks. In short. Learn what DMVPN is, mechanisms used (NHRP, mGRE, IPSec) to achieve of the audience’s potential knowledge levels and explained it in terms that don’t.

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Multipoint GRE, as the name implies allows us to have multiple destinations. DMVPN provides a number of benefits which have helped make them very popular and highly recommended. It should look for a better way using NHRP resolution.

Understanding Cisco DMVPN

Right now we have a hub and spoke topology. Because all spoke-to-spoke traffic in DMVPN Phase1 always traverses the hub, it is actually inefficient to even send the entire routing table from the hub to the spokes. Forum Replies Rene, When would we choose to use Phase 1, 2, or 3, and why? Our hub router will be the NHRP server and all other routers will be the spokes.

Spoke3 replies directly to Spoke2 with its mapping information. DMVPN consists of two mainly deployment designs:.

This sounds pretty cool but it introduces some problems…. In an old postdatedI explained various types of VPN technologies.

Understanding Cisco Dynamic Multipoint VPN – DMVPN, mGRE, NHRP

The Dnvpn router checks its cache, finds an entry for spoke 2 and sends the NHRP resolution reply to spoke1 with the public IP address of spoke2. Hello Heng This is a very good question. Send this to a friend Your email Recipient email Send Cancel.


Lastly, traffic between spokes in a point-to-point GRE VPN explakned must pass through the hub, wasting valuable bandwidth and introducing unnecessary bottlenecks. Hello Lagapides Thank you so much for vmvpn time. Each router is connected to the Internet and has a public IP address:. In addition, the hub router has three GRE tunnels configured, one for each spoke, making the overall configuration more complicated. We use cookies to give you the best personal experience on our website.

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Introduction to DMVPN |

Routed versus routing protocols Send WhatsApp alert during a network fault. Unified Communications Components – Understanding Your By using our website, you agree to our use of cookies Read more. When there is traffic between the branch offices, we can tunnel it directly instead of sending it through the HQ router. When we use GRE Multipoint, there will be only one tunnel interface on each router.

Furthermore, spoke-to-spoke traffic no longer needs to pass through the hub router but is sent directly from one spoke to another. In case no routing protocol is used in our VPN network, the addition of one more spoke would mean configuration changes to all routers so that the new spoke is reachable by everyone. explainsd


This means that there will be no direct spoke-to-spoke communication, all traffic has to go through the hub! Cisco DMVPN uses a centralized architecture to provide easier implementation and management for deployments that require granular access controls for diverse explqined communities, including mobile workers, telecommuters, and extranet users.

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Looking at exxplained process in more detail, when using Phase 3. Above we have one router that represents the HQ and there are four branch offices. Web Vulnerability Scanner Free Download. The hub router is configured with three separate tunnel interfaces, one for each spoke:. This is great, we only required the hub to figure out what the public IP address is and all traffic can be sent from spoke to spoke directly.

The HQ for example has one tunnel with each branch office as its destination. When we use them, our picture could look like this:. The hub router will dynamically accept spoke routers. If you like to keep on reading, Become a Member Now! At this point, the spokes can now modify their routing table entries to reflect the NHRP shortcut route and use it to reach the remote spoke.