Azure VNet and Firewalls

Azure Virtual Network (VNet) is a logically isolated network in Azure that enables you to securely connect Azure resources to each other, as well as to on-premises resources. It allows you to create your own network in Azure, and configure the network settings, such as subnets and security rules, to meet your specific needs.

One of the key security features of Azure VNet is the ability to use Azure Firewall to protect your resources from external threats. Azure Firewall is a cloud-based network security service that provides stateful firewall protection for Azure Virtual Network resources. It allows you to create and enforce rules for inbound and outbound traffic, and can be used to protect against common network attacks, such as denial of service (DoS) and man-in-the-middle (MITM) attacks.

In this article, we will look at how to create an Azure VNet and configure an Azure Firewall to protect it.

Prerequisites

Before we get started, there are a few prerequisites that you will need:

• An Azure account. If you don’t have one, you can sign up for a free trial at https://azure.com.
• The Azure CLI. You can install it from the Azure website.

Creating an Azure VNet

To create an Azure VNet, follow these steps:

1. Open a terminal window and log in to Azure using the Azure CLI:

az login

2. Create a resource group to hold your VNet and other resources:

az group create --name myResourceGroup --location eastus

3. Create a VNet and a subnet within the VNet:

az network vnet create --resource-group myResourceGroup --name myVNet --address-prefixes 10.0.0.0/16 --subnet-name mySubnet --subnet-prefix10.0.0.0/24

This will create a new VNet with a single subnet, and assign it the address range 10.0.0.0/16.

Configuring an Azure Firewall

To configure an Azure Firewall to protect your VNet, follow these steps:

1. Create an Azure Firewall:

az network firewall create --resource-group myResourceGroup --namemyFirewall --location eastus --vnet-name myVNet --public-ip-addressesmyFirewallPublicIP

2. Create a rule to allow inbound traffic from the Internet:

az network firewall network-rule create --resource-group myResourceGroup --firewall-name myFirewall --name allowHttp --protocols Tcp --source-addresses '*' --source-ports '*' --destination-addresses '*' --destination-ports 80

This will create a rule that allows inbound traffic on TCP port 80 (HTTP) from any source address.

3. Create a rule to allow outbound traffic to the Internet:

az network firewall network-rule create --resource-group myResourceGroup --firewall-name myFirewall --name allowInternet --protocols Tcp --source-addresses '*' --source-ports '*' --destination-addresses '*' --dest