Azure Firewall vs Network Security Group (NSG) vs Web Application Firewall (WAF) – A Comprehensive Comparison

1. Overview

Azure Firewall

  • Description: Azure Firewall is a fully managed, cloud-native network security service that protects your Azure Virtual Network resources.

Network Security Group (NSG)

  • Description: NSGs act as a basic form of firewalling at the networking layer and can be associated with subnets, network interfaces, or individual VMs.

Web Application Firewall (WAF)

  • Description: WAF helps protect web applications from common web vulnerabilities and exploits. It is typically deployed in front of web applications to filter and monitor HTTP traffic.

2. Key Features

Azure Firewall

  • Centralized Management: Centrally create, enforce, and log application and network connectivity policies.
  • Threat Intelligence-Based Filtering: Integrates with Azure Threat Intelligence to provide protection against known malicious IP addresses and domains.

Network Security Group (NSG)

  • Stateful Filtering: Provides stateful packet inspection.
  • Rule-Based Security: Allows or denies traffic based on rules defined by the user.

Web Application Firewall (WAF)

  • Web Application Protection: Filters, monitors, and blocks HTTP traffic to and from a web application.
  • OWASP Top 10 Protection: Helps protect against common web application vulnerabilities outlined by the Open Web Application Security Project (OWASP).

3. Use Cases

Azure Firewall

  • Network Security: Protects Azure Virtual Network resources.
  • Centralized Control: Suitable for organizations requiring centralized management of network security policies.

Network Security Group (NSG)

  • Network Segmentation: Useful for segmenting and securing virtual networks.
  • Basic Network Security: Provides a basic level of network security.

Web Application Firewall (WAF)

  • Web Application Protection: Essential for securing web applications against common web vulnerabilities.
  • Application Layer Security: Focuses on protecting the application layer of the OSI model.

4. Performance

Azure Firewall

  • Scalability: Scales horizontally to handle increased traffic.
  • Throughput: High throughput capabilities.

Network Security Group (NSG)

  • Basic Performance: Suitable for basic networking needs.
  • Limited Scalability: May not scale as efficiently as dedicated firewall solutions.

Web Application Firewall (WAF)

  • Performance Impact: May introduce latency due to deep packet inspection.
  • Throughput: Depends on the chosen WAF solution and its capabilities.

5. Integration with Azure Services

Azure Firewall

  • Deep Azure Integration: Integrates seamlessly with Azure services, including Azure Monitor for logging.

Network Security Group (NSG)

  • Basic Integration: Integrates with Azure services but lacks some advanced features of dedicated firewall solutions.

Web Application Firewall (WAF)

  • Application Gateway Integration: Often integrated with Azure Application Gateway for web application protection.

6. Cost Management

Azure Firewall

  • Pay-Per-Use Model: Billed based on consumption.
  • Scalability: Cost scales with usage.

Network Security Group (NSG)

  • Included in Azure Subscription: Part of Azure subscription costs.
  • Resource-Specific Costs: Costs may vary based on the resources associated with NSGs.

Web Application Firewall (WAF)

  • Varied Pricing: Pricing depends on the chosen WAF solution and its features.
  • Scalability: Costs may scale with usage.

7. Ease of Management

Azure Firewall

  • Centralized Policy Management: Centrally manage policies for multiple applications and networks.
  • Azure Portal Integration: Accessible through the Azure Portal.

Network Security Group (NSG)

  • Resource-Specific Policies: Policies associated with individual resources.
  • Azure Portal Integration: Managed through the Azure Portal.

Web Application Firewall (WAF)

  • Web Application-Centric Management: Primarily managed in the context of web applications.
  • Azure Portal Integration: Managed through the Azure Portal.

This comprehensive comparison should provide insights into the strengths and use cases of Azure Firewall, NSG, and WAF in Azure. Consider your specific requirements, performance needs, and integration preferences when choosing the right security solution for your Azure environment.


FeatureAzure FirewallNetwork Security Group (NSG)Web Application Firewall (WAF)
OverviewFully managed, cloud-native network security service for Azure Virtual Network resources.Basic form of firewalling at the networking layer, associated with subnets, network interfaces, or VMs.Protects web applications from common web vulnerabilities and exploits, typically deployed in front of web applications.
Key FeaturesCentralized Management, Threat Intelligence-Based FilteringStateful Filtering, Rule-Based SecurityWeb Application Protection, OWASP Top 10 Protection
Use CasesNetwork Security, Centralized ControlNetwork Segmentation, Basic Network SecurityWeb Application Protection, Application Layer Security
PerformanceScalability, High ThroughputBasic Performance, Limited ScalabilityPerformance Impact (latency may increase), Throughput depends on the chosen WAF solution.
Integration with Azure ServicesDeep Azure Integration, Azure Monitor IntegrationBasic Integration with Azure ServicesApplication Gateway Integration, Integration with Azure services depending on the chosen solution.
Cost ManagementPay-Per-Use Model, ScalabilityIncluded in Azure Subscription, Resource-Specific CostsVaried Pricing, Scalability with Usage
Ease of ManagementCentralized Policy Management, Azure Portal IntegrationResource-Specific Policies, Azure Portal IntegrationWeb Application-Centric Management, Azure Portal Integration