Mastering Azure Firewall REST API: Advanced DNAT, IDPS, and Web Filtering Techniques for Enhanced Network Security

Dive deeper into Azure Firewall REST API with Part II of this series! Learn advanced configurations like DNAT rules, IDPS setup, web category filtering, FQDN and URL filtering, multi-IP association, and diagnostic logging to secure and scale your Azure network effectively. Unique :

Getting Advanced with Azure Firewall REST API – Part II

In the first part of this series, we covered the basics of provisioning and managing Azure Firewall using REST API. Now, Part II dives deeper into advanced configurations. These updates are essential for securing complex, large-scale environments and boosting your network’s security posture.

What’s New in Azure Firewall REST API?

This installment introduces key features like DNAT rules, Intrusion Detection and Prevention System (IDPS), web category filtering, FQDN and URL filtering, and more. Plus, you’ll learn how to associate multiple public IPs and enable detailed diagnostics for better monitoring.

“By the end of this part, you’ll have a deeper understanding of how to leverage Azure Firewall’s full potential to meet real-world enterprise security needs—using REST API.”

Initial Setup: Authentication and Prerequisites

Start by creating a Service Principal with Azure CLI to authenticate your REST API requests. Use the command:

az ad sp create-for-rbac --name "BrunoClient" --role Contributor --scopes /subscriptions/{subscription-id}

Next, obtain a Bearer Token via Bruno or any REST client. Remember, tokens expire roughly every hour, so refresh them regularly.

Major Updates: DNAT Rules and IDPS

Configuring DNAT Rules

DNAT rules let you securely expose internal resources by redirecting traffic from a public IP and port to an internal FQDN and port. This is crucial for managing inbound traffic efficiently.

Enabling Intrusion Detection and Prevention (IDPS)

Azure Firewall Premium supports IDPS to monitor and block suspicious activities. You can customize signature overrides and create bypass rules for trusted traffic.

“This configuration provides flexibility to fine-tune your threat detection settings while allowing exception/safe traffic to pass without inspection.”

Web Categories, FQDN, and URL Filtering

Azure Firewall lets you filter outbound traffic based on web categories like Social Networking or Gambling. This simplifies policy enforcement across large networks.

FQDN filtering controls access based on domain names without decrypting traffic, preserving privacy and performance. URL filtering goes even further by allowing or denying specific URLs or paths.

Additional Features to Know

Associate multiple public IP addresses with your Azure Firewall for better scalability.
Enable diagnostic settings for detailed logging and monitoring, crucial for security audits.
Customize SNAT private IP address ranges to precisely control outbound traffic.

Why This Matters

These advanced REST API configurations empower network admins and security pros to tailor Azure Firewall to complex enterprise needs. Automation through REST API means faster deployments and consistent security policies.

Ready to level up your Azure Firewall game? This guide is your next step toward mastering network security automation.

Set up authentication with Azure Service Principal and manage Bearer Tokens for API access.

Configure DNAT rules to securely expose internal resources via public IPs and ports.

Enable and customize Intrusion Detection and Prevention System (IDPS) with signature overrides and bypass rules.

Use web category filtering to block or allow entire categories of websites, enhancing policy enforcement.

Leverage FQDN and URL filtering rules to control outbound traffic based on domains and specific URLs without decrypting traffic.

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