Azure Route Server

What is Azure Route Server?

Azure Route Server simplifies the management of routing between your virtual networks, on-premises networks, and connectivity providers by automatically learning routes from network virtual appliances (NVAs) and advertising them to your Azure Virtual WAN and VPN gateways. It acts as a central hub for route propagation.

Route Server integrates seamlessly with both Azure Virtual WAN and traditional Virtual Networks. This allows you to peer your NVAs with Route Server and have the routes automatically advertised to your gateways, eliminating the need for manual route configuration and management.

Azure Route Server Architecture Diagram

Tip: Azure Route Server is a fully managed Azure service, reducing the operational overhead associated with managing route propagation.

Key Benefits

  • Simplified Route Management: Automates the learning and advertising of routes, reducing manual configuration errors.
  • Scalability: Designed to scale with your network infrastructure, handling a large number of routes and connections.
  • Reduced Complexity: Eliminates the need for complex BGP configurations for route exchange between NVAs and gateways.
  • Enhanced Connectivity: Enables seamless connectivity between various network environments, including on-premises, multi-cloud, and different Azure regions.
  • Integration: Works with Azure Virtual WAN, VPN Gateways, and ExpressRoute for comprehensive network solutions.

How it Works

Azure Route Server operates by establishing BGP (Border Gateway Protocol) peering with your Network Virtual Appliances (NVAs). Once peered, the NVA can advertise its routes to Route Server. Route Server then takes these learned routes and advertises them to the connected Azure VPN Gateways or Virtual WAN Hubs.

Conversely, Route Server learns routes from the VPN Gateways and Virtual WAN Hubs and advertises them to the NVAs. This bidirectional route exchange ensures that all connected endpoints have the necessary routing information to communicate.

BGP Peering with NVAs

To connect an NVA to Azure Route Server, you need to configure a BGP peering session. This typically involves:

  • Using the Route Server's public IP address as the BGP peer.
  • Configuring the NVA with the Route Server's ASN (Autonomous System Number) and its own ASN.
  • Using private IP addresses within the Route Server's subnet for internal peering.

Integration with Azure Gateways

Azure Route Server is designed to integrate with:

  • Azure Virtual WAN Hubs: You can enable Route Server within a Virtual WAN hub to manage routing for all connected branches and VNets.
  • Azure VPN Gateways: For traditional VNet deployments, Route Server can be deployed as a standalone resource to peer with VPN Gateways.
Route Server Data Flow Diagram

Deployment Scenarios

Azure Route Server is particularly useful in scenarios such as:

  • Centralized Network Virtual Appliances: Deploying firewalls, load balancers, or other NVAs in a hub VNet and using Route Server to distribute their routes to spoke VNets.
  • Multi-Site Connectivity: Managing routing for complex on-premises connectivity scenarios with multiple branch offices.
  • Hybrid Cloud Networking: Facilitating seamless route exchange between Azure and other cloud providers or on-premises data centers.
  • Simplified Branch Connectivity: When using Virtual WAN, Route Server simplifies the connection and routing for SD-WAN appliances.

Getting Started

To get started with Azure Route Server, you'll typically need to:

  1. Deploy an Azure Route Server resource.
  2. Configure BGP peering with your NVAs.
  3. Enable Route Server on your Virtual WAN hub or peer it with your VPN Gateway.
  4. Verify route propagation.

Refer to the official Azure documentation for detailed step-by-step guides and best practices.

For more information, visit the Azure Route Server Overview on Microsoft Docs.