When deploying Azure Firewall, following best practices ensures that your network is secure, scalable, and optimized for performance. This post will guide you through key steps, common configurations, and some advanced strategies for leveraging Azure Firewall within your network. We will also discuss integration with third-party firewalls like Palo Alto and Checkpoint, as well as integrating firewall logs with SIEM solutions such as Azure Sentinel or Splunk for enhanced security monitoring and analytics.

1. Understand Your Network Requirements

Before deploying Azure Firewall, it is essential to evaluate your organization’s network security needs. Begin by mapping out your architecture, including:

• Virtual Network Layout: Define which subnets will require security rules and monitoring.
• Traffic Flow: Ensure proper understanding of how traffic flows through your on-premises network, between subnets, and between different regions in Azure.
• Application and Service Protection: Prioritize which workloads require additional layers of security.

Once you have a comprehensive network diagram, you can design an appropriate Azure Firewall deployment that fits your business objectives.

2. Use Threat Intelligence-Based Filtering

Azure Firewall offers a built-in threat intelligence feature powered by Microsoft Threat Intelligence, which provides up-to-date insights on known malicious IP addresses and domains. When enabled, this feature can block inbound and outbound traffic from/to these addresses, adding an extra layer of protection to your environment.

Best Practices:

• Enable Threat Intelligence Alert Mode to monitor traffic and receive warnings of suspicious activity.
• Use Threat Intelligence Deny Mode to actively block traffic from malicious sources and prevent potential attacks.

3. Network Segmentation and Micro-Segmentation

Implementing network segmentation ensures that different types of traffic are isolated, reducing the risk of lateral movement within the network. Azure Firewall should be positioned between segments to filter and inspect traffic at each boundary.

Best Practices:

• Use Azure Firewall Subnet to ensure isolation between different workloads.
• Implement Network Security Groups (NSGs) alongside the firewall to apply fine-grained security controls for each subnet.

4. Leverage Azure Firewall Policy for Centralized Management

Azure Firewall Policy allows you to manage firewall rules across multiple Azure Firewall instances from a single pane of glass. This ensures consistency in rule application across your infrastructure.

Best Practices:

• Use a Hub-and-Spoke Architecture to route traffic between different Azure regions while managing firewall rules centrally.
• Define a Global Policy for common security rules and create Local Policies for region-specific configurations.

5. Automate Rule Management with Infrastructure-as-Code

Azure Firewall rules can be managed using templates in Infrastructure-as-Code (IaC) tools such as Terraform or Azure Resource Manager (ARM) templates. Automation helps to maintain a versioned, auditable, and reproducible set of configurations.

Best Practices:

• Store firewall rules and policies in a Source Control System such as Git.
• Use CI/CD Pipelines to deploy firewall rules in a controlled and automated manner.

Integrating Third-Party Firewalls: Palo Alto and Checkpoint

While Azure Firewall provides robust, cloud-native security, many organizations prefer or require integration with third-party firewalls like Palo Alto or Checkpoint to leverage additional features or maintain consistency with on-premises infrastructure.

Use Case: Multi-Cloud and Hybrid Deployments

For enterprises with multi-cloud environments or hybrid cloud architectures, integrating third-party firewalls can provide unified policy management across different platforms. In this scenario, deploying Palo Alto or Checkpoint firewalls in Azure ensures that the same set of security policies can be applied to both on-premises and cloud environments.

Best Practices for Third-Party Firewall Integration:

• Virtual Appliances: Deploy Palo Alto or Checkpoint as a virtual appliance in your Azure environment. These firewalls can be provisioned from the Azure Marketplace.
• Route Tables: Use User Defined Routes (UDRs) to ensure traffic is routed through the third-party firewall for inspection.
• High Availability: Set up high availability (HA) to ensure continuous traffic flow and automatic failover in case one instance fails.
• Cost Management: Be mindful of additional costs, such as ingress/egress data transfer charges, when integrating third-party firewalls.

Example Scenario:
An organization uses both Azure and AWS, with Palo Alto firewalls managing traffic across regions. By deploying a Palo Alto firewall in Azure and configuring it with Panorama (Palo Alto’s management tool), they achieve a unified security policy that applies to both clouds. Traffic is routed through the Azure Palo Alto firewall using UDRs, inspected, and then forwarded to internal resources.

Integrating Azure Firewall with SIEM Solutions (Sentinel, Splunk)

A robust logging and monitoring setup is critical for any firewall deployment. Azure Firewall integrates natively with Azure Sentinel, but it can also send logs to third-party SIEM solutions like Splunk for further analysis, correlation, and incident management.

Sending Firewall Logs to Azure Sentinel

Azure Sentinel provides seamless integration with Azure Firewall. You can configure the firewall to send its logs and metrics to Sentinel, where they can be visualized, analyzed, and acted upon through custom alerts.

Best Practices:

• Log Analytics Workspace: Ensure Azure Firewall is sending logs to a Log Analytics workspace, which acts as the source for Sentinel.
• Custom Workbooks: Use custom Sentinel workbooks to visualize firewall traffic, identify threats, and drill down into specific log entries.
• Incident Response: Set up playbooks in Sentinel for automated responses to certain events, such as blocking a suspicious IP address based on a firewall log entry.

Integrating Azure Firewall Logs with Splunk

Splunk can also be used to analyze Azure Firewall traffic by ingesting firewall logs through an event collector or via a Splunk add-on for Azure.

Best Practices:

• Syslog Export: Export Azure Firewall logs to Syslog for ingestion by Splunk.
• Custom Dashboards: Create custom Splunk dashboards that provide insights into traffic patterns, potential attacks, and rule effectiveness.
• Search Queries: Use pre-built or custom search queries to analyze firewall logs, detect anomalies, and trigger alerts in real-time.

Relevant Links

• Azure Firewall Documentation
• Azure Sentinel Documentation
• Palo Alto Firewall in Azure
• Checkpoint Virtual Appliance in Azure
• Splunk Add-on for Microsoft Cloud

Experience lightning-fast speeds and unparalleled reliability. 

Upgrade to Hostinger’s Cloud Professional or Cloud Enterprise plans today and take your online presence to the next level.