How To’s – Deploy DMVPN Dual Hub Single Cloud

Hi there, in this post we're going to deploy DMVPN Dual Hub Single Cloud.

So far we saw how to deploy and secure DMVPN using one Hub and multiple spokes. The problem with previous deployment was that if the Hub became offline, we would lose spoke-to-spoke communication, meaning we had a single point of failure. To overcome this problem, we can deploy two or more Hubs, allowing us to have different scalable topologies.

Let’s begin by configuring New York and London as Hubs.

New York - Hub1

London - Hub2

Now let's configure Dublin and Brussels as spokes.

Dublin - Spoke1

Brussels - Spoke2

Let's check the tunnel status and eigrp routes on London

Everytinhg looks ok from the Hub perspective. Let's look at spoke side:

Without sending any traffic to other spoke, we see that initially the spoke is registered with both Hubs. Now let's test reachability from PC3 (Dublin) to PC4 (Brussels)

PC3 reaches successfully PC4. Now let's test if both Hubs are really providing high availability by shutting down the Hub links one at a time.

We see that Hub1 is offline, but the routes still being advertised from Hub2.

Then I brought Hub1 link back up and shutdown Hub2 link. These tests didn't affect PC3 at all.

We successfully deployed DMVPN Dual Hub Single Cloud.

I hope you enjoyed this post, leave your comments below and I'll see you on the next one.