Virtual WAN Concepts

Azure Virtual WAN is a networking service that brings together many networking, security, and routing functionalities to provide a single operational interface. It's designed to help you manage your cloud and on-premises network connectivity.

Key Components of Virtual WAN

Virtual WAN consists of several key components that work together to provide a scalable and secure networking solution:

1. Virtual WAN Hub

The Virtual WAN hub is a Microsoft-managed network transit center in an Azure region. It acts as a central point of connectivity for your Azure virtual networks, your on-premises sites, and your remote users.

  • Hubs are deployed in an Azure region.
  • They support connectivity to multiple VNets.
  • They provide transit routing between connected VNets and on-premises sites.
  • Security features like Azure Firewall and Network Security Groups (NSGs) can be integrated.

2. Virtual Network Connections

To connect your Azure virtual networks to a Virtual WAN hub, you establish a virtual network connection. This connection allows your VNet resources to communicate through the hub.

  • Each VNet can be connected to one Virtual WAN hub.
  • Connectivity is transitive through the hub.

3. Site-to-Site VPN Connections

Virtual WAN supports connecting your on-premises network locations to your Virtual WAN hub using site-to-site VPNs. This allows your branch offices and data centers to securely connect to your Azure resources.

  • You configure connections from your on-premises VPN devices to the Virtual WAN hub.
  • Virtual WAN simplifies the management of multiple site-to-site connections.

4. Remote User VPN (Point-to-Site)

Virtual WAN enables remote users to connect to your Azure network securely through a point-to-site VPN. This is ideal for employees working remotely who need access to corporate resources.

  • Supports both OpenVPN and IKEv2 VPN protocols.
  • Users can connect from various devices using VPN client software.

5. Router (ExpressRoute)

While not a direct component of Virtual WAN itself, ExpressRoute circuits can be connected to a Virtual WAN hub. This allows for high-bandwidth, low-latency private connections between your on-premises network and Azure.

  • Integrates with existing ExpressRoute deployments.
  • Provides redundant and reliable connectivity.

6. Routing

Virtual WAN includes a sophisticated routing service that automatically learns and propagates routes between connected networks. This simplifies route management and ensures proper traffic flow.

  • Automatic route propagation.
  • Support for custom route tables and propagation policies.
  • Integration with Azure Router Service for advanced routing scenarios.

Benefits of Azure Virtual WAN

  • Centralized Management: A single interface to manage your global network.
  • Scalability: Designed to scale to support large numbers of sites and users.
  • Security: Integrates with Azure Firewall and other security services.
  • Simplified Connectivity: Streamlines the process of connecting VNets, on-premises sites, and remote users.
  • Cost-Effectiveness: Can offer cost savings through optimized bandwidth usage and simplified infrastructure.

Important Note

Understanding the core concepts of Virtual WAN, such as the hub and spoke topology, is crucial for designing and implementing an efficient and secure network architecture in Azure.

Architecture Overview

A typical Virtual WAN architecture involves one or more Virtual WAN hubs deployed in different Azure regions. Virtual networks and on-premises sites are then connected to these hubs. This creates a global transit network, allowing seamless communication between all connected endpoints.

For example:

  • A Virtual WAN hub in Azure East US connects to VNet A (production) and VNet B (development).
  • A VPN connection from an on-premises data center connects to the same hub.
  • Remote users can also connect to this hub.

This setup ensures that resources in VNet A can communicate with resources in VNet B and the on-premises data center, all routed through the Virtual WAN hub.

For more detailed information on specific configurations and advanced features, please refer to the How-to guides.