Transit Networking with Azure Virtual WAN
Azure Virtual WAN provides a simplified, automated, and scalable way to manage your wide area network (WAN). A key aspect of Virtual WAN is its ability to enable transit networking, allowing seamless connectivity between different branches, remote users, and Azure virtual networks.
What is Transit Networking?
Transit networking refers to the ability of a network device or service to route traffic between different, unconnected networks. In the context of Azure Virtual WAN, this means that a Virtual WAN hub can act as a central point for routing traffic between:
- Site-to-site VPN connections (branch offices).
- Remote user VPN connections (point-to-site).
- Azure Virtual Networks (VNets).
- Azure ExpressRoute connections.
How Virtual WAN Enables Transit
The Virtual WAN hub is the core component that facilitates transit networking. It's a managed Microsoft service that aggregates multiple connectivity options and provides advanced routing capabilities. When you connect different resources to a Virtual WAN hub, the hub automatically learns the routes and forwards traffic appropriately.
Key Components and Concepts:
- Virtual WAN Hub: A fully managed, scalable hub deployed in an Azure region. It acts as the central point for all connections.
- Virtual Network Connections: VNets can be connected to the Virtual WAN hub. Traffic from VNets connected to the hub can be routed to other connected VNets, VPN sites, or remote users.
- Site-to-Site VPN: Branch offices can connect to the Virtual WAN hub via VPN tunnels. The hub then enables transit between these sites and other connected resources.
- Point-to-Site VPN: Remote users can connect to the Virtual WAN hub using VPN clients. This allows them to access resources across your connected network.
- ExpressRoute: For high-bandwidth, low-latency connections, ExpressRoute circuits can be connected to the Virtual WAN hub, providing private connectivity between on-premises networks and Azure.
- Route Tables: Virtual WAN utilizes route tables within the hub to manage and propagate routes. This ensures that devices know how to reach destinations in other connected networks.
Benefits of Transit Networking with Virtual WAN
- Simplified Management: Reduces the complexity of managing multiple VPN gateways and complex routing configurations.
- Scalability: The Virtual WAN hub is designed to scale automatically to meet your bandwidth and connectivity demands.
- Global Reach: Connect your global branches and users to Azure seamlessly.
- Enhanced Security: Centralized security policies can be applied at the hub level.
- Cost-Effectiveness: Often more cost-effective than building a traditional hub-and-spoke topology with separate VPN gateways.
Example Scenario:
Imagine you have two branch offices (Branch A and Branch B) and two Azure VNets (VNet 1 and VNet 2). If both branches and VNets are connected to the same Virtual WAN hub:
- Branch A can communicate with Branch B directly through the hub.
- Branch A can communicate with resources in VNet 1 and VNet 2.
- VNet 1 can communicate with VNet 2.
- Remote users connected via point-to-site VPN can access resources in both branches and VNets.
Configuration Considerations
When setting up Virtual WAN for transit networking, pay attention to:
- Hub Route Propagation: Configure route tables to propagate learned routes to the desired connections.
- Firewall Integration: Consider integrating Azure Firewall in the Virtual WAN hub for centralized traffic inspection and security.
- IP Addressing: Plan your IP address spaces carefully to avoid overlaps between on-premises networks and Azure VNets.
Azure Virtual WAN simplifies the complexities of modern networking, providing a robust and scalable platform for achieving comprehensive transit connectivity across your hybrid cloud environment.
For more detailed configuration guidance, please refer to the official Azure Virtual WAN documentation.