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.
|Published (Last):||3 September 2016|
|PDF File Size:||11.89 Mb|
|ePub File Size:||8.61 Mb|
|Price:||Free* [*Free Regsitration Required]|
The hub is the only router that is using a multipoint GRE interface, all spokes will be using regular point-to-point GRE tunnel interfaces.
It needs to figure out the destination public IP address of spoke2 so it will send a NHRP resolution requestasking the Hub router what the public IP address of spoke 2 is. Above we have two spoke routers NHRP clients which establish a tunnel to the hub router. Each router is connected to the Internet and has a public IP address:.
You may cancel your monthly membership at any time. When would we choose to use Phase 1, 2, or 3, and why? Subscribe to our RSS Feed! This sounds pretty cool but it introduces some problems….
Since our traffic has to go through the hub, our routing configuration will be quite simple. Explained As Simple As Possible. Join us on Facebbook!
An explainec by Fabio Semperboni Tutorial. Continue reading in our forum. The hub router is configured with three separate tunnel interfaces, one for each spoke:. In an old postdatedI explained various types of VPN technologies.
As you can notice, the network 1 Multipoint GRE, as the name implies allows us to have multiple destinations. Lastly, traffic between spokes in a point-to-point GRE VPN network must pass through the hub, wasting valuable bandwidth and introducing unnecessary bottlenecks.
Understanding Cisco Dynamic Multipoint VPN – DMVPN, mGRE, NHRP
Routed versus routing protocols Send WhatsApp alert during a network fault. DMVPN provides a number of benefits which have helped make them very popular and highly recommended. The Hub 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. The request gets forwarded from HUB to Spoke3.
When there is traffic between the branch offices, we can tunnel it directly instead of sending it through the HQ router.
Join us on LinkedIn! It is important to note that mGRE interfaces do not have a tunnel destination.
Introduction to DMVPN |
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. DMVPN consists of two mainly deployment designs:. Cisco DMVPN uses a centralized architecture to provide easier implementation and explaijed for deployments that require granular access controls for diverse user communities, including mobile workers, telecommuters, and extranet users.
Follow Explainned on Twitter! Share on Facebook Share. Spoke3 replies directly to Spoke2 with its mapping information.
The HQ for example has one tunnel with each branch office as its destination. In addition, the hub router has three GRE tunnels configured, one for each spoke, making the overall configuration more complicated. Articles To Read Next: 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.
This means that there will be no direct spoke-to-spoke communication, all traffic has to go through the hub! Furthermore, spoke-to-spoke traffic no longer needs to pass through the hub router but is sent directly from one spoke to another.
Full Access to our Lessons. When we use them, our picture could look like this:. In phase 2, all spoke routers use multipoint GRE tunnels so we do have direct spoke to spoke tunneling. Hello Heng This is a very good question.
Initially, and that is the key word all spoke to spoke explaibed are switched across the hub.