Create a Hub-and-Spoke topology with Azure Virtual Network Peering

Currently I’m working on AZ-102 certification and I wanted to share with you a small lab I created to try Azure virtual network and especially remote gateway. To create a Hub-and-Spoke topology, you need that each spoke virtual network communicates through the hub virtual network. To implement this kind of solution, you need several virtual networks and peering. I would like to implement the following solution:

All VMs must be able to communicate through NE01-VMProject1 which is the hub. A peering will be established between NE01-NET – NE02-NET and NE01-NET – NE03-NET. To prepare this topic, I’ve already created the following resources:

• Resource groups
• Virtual machines
• Virtual networks

As you can see below, the VM NE01VM1 is connected to NE01-NET virtual network with the IP 10.11.0.4.

The VM NE02VM1 is connected to NE02-NET virtual network with the IP 10.12.0.4.

Because no peering is created, a VM cannot ping another:

Create the peering

First, I edit Peerings from NE02-NET.

I call it NE02-NET-NE01-NET and I select the virtual network NE01-NET. For the moment, I leave default configuration.

From NE01-NET virtual network, I do the same thing to peer it to NE02-NET. I leave also the default configuration for the moment.

When peers are created, you should get the peering status to Connected.

Now, VM from NE01-VMProject1 and NE02-VMProject2 are able to communicate:

So, I create the peers between NE03-VMProject3 and NE01-VMProject1. I repeat the same steps as previously. I create a peer from NE01-NET to connect to NE03-NET.

Then I create a peer from NE03-NET to connect to NE01-NET.

From this point, VMs from NE03-VMProject3 are able to communicate with NE01-VMProject1 VMs and VMs from NE02-VMProject2 can ping VM from NE01-VMProject1. However, VM from NE03-VMProject3 can’t communicate with NE02-VMProject2 because gateway and routes are missing:

Create virtual gateway and route tables

First, create a virtual gateway in your hub network (NE01-NET) with the following settings. The gateway takes the 4^th IP address in gateway subnet. You need this information for later. So, in this example, the internal IP address of this virtual network gateway is 10.11.1.4.

Then in NE02-VMProject2 and NE03-VMProject3, create a route table resource with the following settings:

Now, navigate in route table resource and click on Routes. Click on Add.

Configure the route as the following:

	Route Name	Address prefix	Next hop type	Next hop address
NE02-NET-ROUTE	To-NE03-NET	10.13.0.0/16	Virtual appliance	10.11.1.4
NE03-NET-ROUTE	To-NE02-NET	10.12.0.0/16	Virtual appliance	10.11.1.4

Now, click on Subnet and Associate.

Associate the NE02-NET-ROUTE to NE02-NET virtual network and NE03-NET-ROUTE to NE03-NET.

Configure hub peers

Now we need to allow gateway transit in each hub peer. Open each peering configuration in NE01-NET and Allow gateway transit as below.

Configure spoke peers

In each spoke peer (NE02-NET and NE03-NET), enable Use remote gateways option.

Wait a few minutes and then all VMs should be able to communicate.