azure By DevTechToday June 28, 2024

A Comprehensive Guide To Azure Firewall 

Are you haunted by the thought of security breaches empowering threat actors to harm the overall security architecture? Do not let this thought disturb your sleep! We have one guard with unimaginable strength to work as the wall of protection—Azure Firewall

Azure Firewall helps you secure your Azure resources and arm your virtual private traffic with an intelligent wall to ensure that only authenticated workloads run in Azure. You have two choices to serve this purpose: Azure Firewall and Network Security Groups (NSG). When you examine Azure Firewall’s performance on five pillars, i.e., security, reliability, cost optimization, performance efficiency, and operational excellence, it tops the list among security tools available to protect your Azure resources. 

This article will explain how Azure Firewall helps you protect against inbound and outbound traffic threats.  

Welcome! Get ready to explore the world where your Azure Infrastructures is armored with Azure Firewall!

What is Azure Firewall?

Azure Firewall is a robust security solution that manages Azure’s security posture. It’s like having a digital barrier that fortifies your cloud resources from threat actors. 

Visualize your inbound and outbound traffic network as cars move along a highway. A Firewall serves the duty of a traffic cop who inspects each passing vehicle with pre-defined policies. With well-established rules, access each package carried by car and identify whether it is allowed or not. This screening process restricts unauthorized access, data breaches, and malicious attacks.

Traffic load needs to pass through this firewall to access your virtual platform. Azure firewall ensures that your Azure resources remain protected. Azure Firewall is in charge of overall security practice, from scanning traffic flow and restricting access for suspicious users to streamlining necessary network traffic information. 

Features Of Azure Firewall

Now that you are well-versed in the Azure Firewall concept, let’s have a look at the features of Azure Firewall:

Unrestricted Cloud Scalability 

This stateful firewall service has unrestricted cloud scalability. This solution scales resources gradually when average CPU consumption or throughput increases.

Availability Zones 

A Firewall might be present across multiple Availability Zones or empower organizations to limit them to specific zones. You are not required to pay any extra charges for these Availability zones. However, data transfer charges depend on the availability zones where the data transfer occurs. 

High Availability 

Azure Firewall is a weapon equipped with built-in high Availability. It doesn’t require additional configuration or extra services for high uptime. 

Service Tags

Service Tags, a label that indicates IP addresses for Container Registry, Azure Key Value, and other services. These are managed wholly by Microsoft and are unchangeable. The firewall empowers filter rules considering these. 

Threat Intelligence

Microsoft has prepared a threat intelligence field that notes domains and sources considered malicious. Azure firewall has the potential to filter connections to alert the users or deny them based on this list.

How Does Azure Firewall Work?

Azure Firewall is an intelligent firewall designed specifically to protect the Microsoft Azure cloud environment. By configuring the Azure firewall, companies ensure that users moving from one spoke VNet to another first navigate the Firewall and then enter their platform if they qualify the security check by Firewall. But how does it actually work?

  • Firewall gets data packets through external sources 
  • Pre-defined rules act as parameters to check these data packets 
  • Additional security checks like malicious payload or IP address assessment are also performed
  • In the next step, it determines from the above assessment whether to deny or allow users to proceed to target resources 
  • Once decided, the ideal action is performed, and information on these packets is logged for further analysis

Azure Firewall Versions

Azure Firewall is available in three versions: Basic, Standard, and Premium. Each version serves unique security requirements. 

Azure Firewall Basic

This solution is specially designed for small and medium-sized businesses (SMBs) to safeguard their Azure Virtual Network Resources. It streamlines security services at an affordable amount. 

Azure Firewall Standard 

Azure Firewall Standard well-suite customers require a Layer 3-Layer 7 Firewall and are looking for autoscaling to manage peak traffic duration of up to 30 Gbps. Furthermore, Enterprise features like DNS proxy, threat intelligence, web categories, and custom DNS are supported in Azure Firewall Standard.

Azure Firewall Premium 

Azure Firewall Premium is ideal for sensitive applications like payment processing. It leverages advanced threat protection potential, such as TLS inspection and malware. 

Azure Firewall Issues and Mitigation

There are a few issues while working with Azure Firewall. But never forget that each problem has a solution. Let’s dive into them one by one:

Conflict with Azure Security Center Just-In-TimeAzure Firewall will not work when JIT is used to access Virtual Machines in a subset with user-defined routesBy Placing JIT Virtual Machines on a separate subnet to the firewall without user-defined routes, Azure Firewall will smoothly operate 
Hub and Spoke with global integration isn’t compatible with the firewall When working with the Hub & Spoke model, wherein in one region is a hub and firewall while in another, there are spokes. It is not feasible in the firewall to connect to the hub through Global VNet Peering.  Azure Firewall Manager can manage multiple firewalls for inter-regional connectivity, or ExpressRoute gateways/VPN can be used for connectivity.
FQDN tags require a protocol: port to be setWith FQDN tags, Application rules require port: A protocol definitionHttps can be used as the port: protocol value. In a short duration, there will be chances of making this field optional while using FQDN tags. 
Lacks support for ICMP trafficInternet Control Message Protocol isn’t natively supported by FirewallBy configuring VPN gateways to enable ICMP support in Azure Firewall

Azure Firewall is one of the top Azure security tools, with an unparalleled capacity to defend your resources. The above-mentioned inbound traffic security check insights help us relax as our resources are conserved. 


In conclusion, Safeguarding your cloud infrastructure with Azure Firewall will help you witness the paradigm shift. As we know, Azure Firewall is an essential security service that guards your infrastructure from attacks and intrusion. Traditional solutions are no longer sufficient. With more and more companies moving towards a cloud infrastructure to safeguard them, advanced approaches are pivotal. And what else can be better than Azure Firewall? Azure Integration Services can aid you in smoothly integrating Azure Firewall. Secure your cloud resources with Confidence. 

Happy Clouding! 

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