Azure Traffic Manager with Virtual WAN

This article provides an overview of how to use Azure Traffic Manager to manage traffic flow for your Virtual WAN deployments. Traffic Manager is a DNS-based traffic load balancer that enables you to distribute traffic optimally to your services hosted in Azure and globally. When combined with Virtual WAN, you can achieve highly available and resilient network architectures.

What is Azure Traffic Manager?

Azure Traffic Manager uses the Domain Name System (DNS) to route client requests to the most appropriate endpoint based on a traffic-routing method. Traffic Manager also provides health monitoring for the endpoints to automatically and continuously direct traffic to healthy endpoints only.

Key Benefits:

  • High Availability: Routes traffic away from unhealthy endpoints to ensure service continuity.
  • Performance Optimization: Directs users to the closest endpoint for reduced latency.
  • Geographic Distribution: Distributes traffic across multiple regions.
  • Improved Application Responsiveness: Enhances user experience by providing fast and reliable access.

Integrating Traffic Manager with Virtual WAN

Virtual WAN provides a central hub for your network traffic. By integrating Traffic Manager, you can ensure that traffic destined for applications or services accessible through your Virtual WAN is intelligently routed.

Common Scenarios:

  • Global Application Load Balancing: Deploy your application in multiple Azure regions and use Traffic Manager to direct users to the closest or best-performing instance. Virtual WAN can then connect these regional deployments.
  • Disaster Recovery: Configure Traffic Manager with failover routing methods to automatically switch traffic to a secondary region in case of a primary region outage.
  • Hybrid Cloud Connectivity: Route on-premises traffic to the most appropriate Azure Virtual WAN hub based on performance or availability.

Configuring Traffic Manager with Virtual WAN

The configuration typically involves these steps:

  1. Deploy Virtual WAN: Set up your Virtual WAN hub(s) in the desired Azure regions and connect your VNets and on-premises sites.
  2. Deploy Application Endpoints: Deploy your application instances in each region where you want to offer it. These could be Azure App Services, Virtual Machines, or other services.
  3. Create Traffic Manager Profile: In the Azure portal, create a new Traffic Manager profile.
  4. Configure Routing Method: Select a traffic-routing method (e.g., Performance, Geographic, Priority, Weighted, Multivalue, Subnet). For Virtual WAN, Priority or Performance are often good choices.
  5. Add Endpoints: Add the public IP addresses or FQDNs of your application endpoints as endpoints in the Traffic Manager profile. If your application is behind a Load Balancer within a VNet connected to Virtual WAN, you'll point to the public IP or FQDN of that Load Balancer.
  6. Configure Health Probes: Set up health probes to monitor the status of each endpoint.
  7. DNS Resolution: Users will access your application using the DNS name provided by Traffic Manager (e.g., myapp.trafficmanager.net). This DNS name resolves to the IP address of the chosen endpoint based on the Traffic Manager configuration.
Note: Ensure that your Virtual WAN is configured to route traffic correctly to the VNet where your application endpoints are hosted. This might involve configuring route tables and user-defined routes (UDRs) within your VNet and potentially propagating routes from the Virtual WAN hub.

Traffic Routing Methods and Virtual WAN

Choosing the right routing method is crucial for effective traffic management:

  • Performance: Routes traffic to the endpoint with the lowest latency. Ideal for globally distributed applications.
  • Priority: Provides simple failover. Traffic is sent to the primary endpoint, and if it's unhealthy, it fails over to the secondary. This is excellent for disaster recovery scenarios with Virtual WAN.
  • Weighted: Distributes traffic based on assigned weights. Useful for gradual rollouts or A/B testing.
  • Geographic: Routes users to endpoints in the same geographic location.

Monitoring and Management

Azure Traffic Manager provides robust monitoring capabilities. You can view traffic patterns, endpoint health, and performance metrics directly in the Azure portal. Alerts can be configured to notify you of any issues with your endpoints or routing configurations.

Tip: Regularly review your Traffic Manager health probes and routing configurations to ensure they align with your business continuity and performance objectives, especially when changes are made to your Virtual WAN infrastructure.

Next Steps