Azure Network Security Overview

What is Azure Network Security?

Azure Network Security provides a robust set of services designed to protect your cloud infrastructure and applications from a wide range of network-based threats. It encompasses various layers of defense, from perimeter protection to granular access control within your virtual networks.

By leveraging Azure's advanced security features, organizations can ensure the integrity, availability, and confidentiality of their data and services, meeting compliance requirements and building trust.

Key Pillars of Azure Network Security

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Perimeter Security

Defend your network edge with services like Azure Firewall and DDoS Protection to block malicious traffic before it reaches your resources.

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Network Segmentation

Implement micro-segmentation using Network Security Groups (NSGs) and Azure Firewall to control traffic flow between different parts of your network.

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Secure Connectivity

Ensure secure communication between your on-premises networks and Azure, or between different virtual networks, using VPN Gateway and ExpressRoute.

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Application Protection

Protect your web applications from common web exploits and bots with Azure Web Application Firewall (WAF).

Core Azure Network Security Services

Azure Firewall

A managed, cloud-based network security service that protects your Azure Virtual Network resources. It offers threat intelligence-based filtering, application, and network-level connectivity policies.

Azure DDoS Protection

Provides enhanced DDoS mitigation capabilities to protect your Azure resources. It includes adaptive tuning, attack analytics, and mitigation reports.

Network Security Groups (NSGs)

NSGs act as a virtual firewall for your VMs and other network resources, allowing you to filter network traffic to and from Azure resources in an Azure virtual network.

Azure Virtual Network (VNet)

The building block for your private network in Azure. VNets enable you to provision and manage Azure resources, providing a secure and isolated environment.

Azure Private Link

Allows you to access Azure PaaS services and Azure hosted customer-owned services over a private endpoint within your virtual network, enhancing data privacy and security.

Azure Web Application Firewall (WAF)

A cloud-native WAF service that helps protect your web applications from common exploits and vulnerabilities, such as SQL injection, cross-site scripting, and more.

How It Works

Azure Network Security operates on multiple levels to provide defense in depth:

Ingress Filtering: Controls traffic entering your virtual network.
Egress Filtering: Controls traffic leaving your virtual network.
Network Segmentation: Isolates workloads and restricts lateral movement of threats.
Threat Detection: Identifies and alerts on malicious activities.
Secure Connectivity: Encrypts traffic between networks.

Consider a typical scenario where you deploy a web application:

// Conceptual flow:
// 1. User requests access to your web application.
// 2. Azure DDoS Protection mitigates volumetric attacks.
// 3. Azure WAF inspects HTTP/S requests for common web exploits.
// 4. Azure Firewall filters traffic based on defined network policies.
// 5. NSGs on your VMs allow or deny traffic based on port and protocol.
// 6. Traffic is routed through your Azure Virtual Network.

Best Practices

Implement a least privilege principle for network access.
Utilize NSGs for micro-segmentation within your virtual networks.
Deploy Azure Firewall for centralized network control and threat intelligence.
Configure DDoS Protection Standard for critical workloads.
Use Azure Private Link for secure access to PaaS services.
Regularly review and audit your network security configurations.