Overview: This lab demonstrates configuring an Azure Firewall to secure Azure resources. The focus is on deploying the firewall, setting up rules, and validating its effectiveness through testing and monitoring.
Prerequisites: ✅ Active Azure subscription with sufficient permissions (Owner/Contributor/Network Contributor). ✅ A virtual network with at least two subnets (AzureFirewallSubnet and VMSubnet). ✅ Networking knowledge for subnets, routing, and security rules. ✅ A test virtual machine to validate firewall rules. ✅ Diagnostic settings enabled for Azure Firewall.
High-Level Steps with Explanations:
1: Use a template to deploy the lab environment: I start by using a pre-configured ARM template to deploy the foundational lab environment. This includes setting up a virtual network with required subnets and resources and ensuring I have the necessary infrastructure to work with Azure Firewall.
2: Deploy an Azure firewall: Next, I deploy an Azure Firewall in the dedicated AzureFirewallSubnet. This will be a centralized, cloud-native security solution to protect and monitor traffic across my virtual network.
3: Create a default route: To route all traffic through the Azure Firewall, I configure a default route in the route table associated with the VM subnet. This ensures all outbound and inbound traffic passes through the firewall for inspection.
4: Configure an application rule: I created an application rule in the Azure Firewall to control outbound web traffic based on specific FQDNs. This will allow or deny access to certain websites, ensuring application-layer security.
5: Configure a network rule: I set up a rule to allow or block specific traffic based on protocol, source, destination, and ports. This enables me to define more granular control over my network traffic.
6: Configure DNS servers: I configure DNS servers for the Azure Firewall to resolve domain names efficiently and ensure the firewall can correctly process application rules that rely on FQDN filtering.
7: Test the firewall: I deploy a test virtual machine and validate the firewall configuration. I’ll test both allowed and blocked traffic to ensure the rules function as expected and secure the environment.
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