AZ-500 Microsoft Azure Security Technologies Exam

Implement and Harden Azure VPN Tunnels

Azure VPN Gateway secures communication between on-premises networks and Azure virtual networks. It supports both point-to-site (P2S) and site-to-site (S2S) connectivity. For P2S, you can choose certificate-based or Azure Active Directory (Azure AD) authentication to verify client identity. For S2S, you deploy IPsec/IKE tunnels with redundant gateway SKUs and optional BGP peering to improve performance and failover. These features help maintain a secure and reliable network link.

To configure a P2S VPN, start by creating a route-based VPN gateway in Azure. Upload the root certificate’s public key and generate client certificates from it. Install these certificates on each client and define a client address pool that assigns private IPs to them. Next, download the VPN client configuration files for Windows, macOS, or Linux and install them on each device. Finally, test connectivity to ensure your clients can access Azure resources.

To harden your P2S VPN, use Azure AD authentication to enforce multifactor authentication (MFA) and apply Conditional Access policies. Customize IPsec policies by selecting strong encryption and integrity algorithms for both Phase 1 and Phase 2. Enforcing Perfect Forward Secrecy (PFS) groups adds another layer of protection. Regularly monitor the VPN tunnel health by checking the gateway’s health probe endpoint. These measures help prevent unauthorized access and keep your VPN secure.

Setting up an S2S VPN starts with a Virtual Network Gateway and a Local Network Gateway configured with your on-premises public IP and address spaces. Ensure your on-premises firewall or VPN device is validated by Azure and that you use a shared key matching exactly on both sides. Choose a redundant gateway SKU for high availability and enable BGP peering to exchange routes dynamically. Confirm your traffic selectors align on both ends to avoid routing issues. This setup delivers an encrypted and high-throughput connection.

When your S2S tunnel has issues, follow these troubleshooting steps to restore connectivity:

• Reset the Azure VPN Gateway and your on-premises VPN device.
• Verify that the shared key matches exactly on both sides.
• Remove any User-Defined Routes (UDR) or Network Security Groups (NSG) from the gateway subnet.
• Check that the external IP of your on-premises device is not included in the Local Network Gateway definitions.
• Ensure address spaces and subnet names match if you are using a policy-based gateway.
  By completing these checks, you can quickly restore your VPN connectivity.

Conclusion

Secure VPN connectivity in Azure relies on strong authentication, robust encryption, and high availability. For point-to-site setups, certificate-based or Azure AD methods let you control client access, and customizing IPsec policies improves security. Site-to-site links use Virtual Network Gateways paired with Local Network Gateways, and enabling BGP peering and redundant SKUs ensures resilient connections. Monitoring tunnel health and following a structured troubleshooting approach keep links running smoothly. By applying these practices, you can securely and reliably connect on-premises networks to Azure.