What is a Subnet?

It’s nothing but a segmentation of a Virtual Network. You can have multiple Subnets in a given VNet. Below is a depiction of a Virtual network with two subnets, one of hosting Web Servers (demo-web-snet) and the other (demo-db-snet) for hosting database servers.

0_physicaldiagram_subnet

In one of my previous articles CREATE VIRTUAL NETWORK (VNET) USING AZURE MANAGEMENT PORTAL, we have created “demo-web-snet” default subnet. Let’s go-ahead and create a new subnet named “demo-db-snet” that would contain all the database related services.

Navigate to the Virtual Network and click on the network “demo-vnet1” to which we would like to add another subnet.

1_selectvnet

As shown in the above screen capture, click on the “Subnets” to navigate to the following subnets that are available in the selected Virtual Network.

2_addsubnet

Now, click on the “Subnet” button as shown in the above screen capture which would navigate to the following blade.

3_createsubnet

Provide a meaningful name and the address range for the subnet as shown above and click on the “OK” button to create the subnet.

That’s it. After a few seconds, the subnet gets added to the VNet as shown below.

4_subnetlisting

Summary: In this article, we have learned what a Subnet and how to create a new Subnet to an existing VNet.

Hope you enjoyed reading the article. Your feedback is much appreciated.