Secure the connectivity of hybrid networks

Hybrid networks combine on-premises infrastructure with cloud services, creating a complex ecosystem that spans across different environments. Ensuring secure connectivity in such a setup is critical to protect data and maintain compliance. This is even more pertinent when preparing for an exam like the AZ-500 Microsoft Azure Security Technologies, which evaluates a candidate’s expertise in securing Azure environments.

Understanding Hybrid Network Connectivity Components

Before diving into securing hybrid networks, it’s essential to understand the components that typically make up hybrid connectivity:

• On-premises Networks: The traditional data centers and private networks within an organization.
• VPN (Virtual Private Network): A secure connection over the internet from on-premises to the cloud provider.
• ExpressRoute: A private connection to Azure services that doesn’t go over the public internet.

Securing VPN Connectivity

When using a VPN to connect to Azure, it is important to establish secure tunnels.

• Site-to-Site VPN: This connects your on-premises VPN device to an Azure VPN Gateway. IPsec/IKE protocols are used for encryption, ensuring the data is secure in transit.
• Point-to-Site VPN: This allows individual devices to connect to Azure securely and is often used for remote workers.

VPN Security Enhancements

• Using Azure VPN Gateway with high-performance SKU for better throughput and encryption capabilities.
• Implementing strong authentication methods such as certificate-based authentication for Point-to-Site VPN connections.
• Regularly updating and patching VPN devices to prevent vulnerabilities.

ExpressRoute Security Considerations

ExpressRoute isn’t inherently encrypted but offers some key security benefits:

• Private Connectivity: Data traveling through ExpressRoute does not pass through the public internet, reducing exposure to internet-based attacks.
• Physical Isolation: The traffic remains isolated from the public internet, which adds an additional layer of security.

To secure ExpressRoute connections you may consider:

• Encrypting sensitive data at the application or transport layer before it travels over ExpressRoute.
• Implementing stringent network security controls at the perimeter of your on-premises network and Azure VNet.

Network Security Groups and Application Security Groups

Network Security Groups (NSGs) allow or deny network traffic to and from Azure resources. They are essential for enforcing a network security policy. Application Security Groups (ASGs) can be used within NSGs to define fine-grained network security policies based on workloads or applications.

Example of using NSGs and ASGs:

Azure Firewall and Web Application Firewall

For a more robust boundary control, Azure Firewall provides a fully stateful firewall as a service with built-in high availability and unrestricted cloud scalability.

• Azure Firewall can filter traffic between VNets and Azure subscriptions, offering threat intelligence-based filtering.
• Web Application Firewall (WAF) is designed to protect HTTP/S traffic at the application layer and can be used with Azure Application Gateway or Azure Front Door service, thus preventing common web vulnerabilities such as SQL injection, cross-site scripting, and others.

Hybrid Security Monitoring and Management

Azure provides tools such as Azure Security Center and Azure Monitor, which can assist with hybrid network security.

• Azure Security Center: Delivers unified security management and advanced threat protection across hybrid cloud workloads.
• Azure Monitor: Collects, analyzes, and acts on telemetry data from Azure and on-premises environments.

Adopting a holistic approach to hybrid network security requires continuous assessment and adaptation to evolving threats. Proper design and implementation of secure connectivity methods, coupled with persistent monitoring, ensure that a hybrid network retains its integrity and resiliency against potential threats. Candidates preparing for the AZ-500 exam should be versed in both the theoretical aspects of these security measures and the practical applications within Azure environments.