Azure Virtual WAN Tutorial: An Introduction

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Okay, here’s a comprehensive article, approximately 5000 words in length, detailing an introduction to Azure Virtual WAN, acting as a tutorial:

Azure Virtual WAN Tutorial: An Introduction – Building a Global, Secure, and Scalable Network

Introduction: The Need for a Modern WAN

In today’s rapidly evolving digital landscape, businesses face increasingly complex networking challenges. Organizations are adopting cloud-first strategies, expanding their global footprint, connecting remote workers, and managing a growing number of applications and devices. Traditional Wide Area Networks (WANs), often built on technologies like Multiprotocol Label Switching (MPLS), can struggle to keep up with these demands. They can be complex to manage, expensive to scale, and lack the agility required for modern cloud-centric environments.

This is where Azure Virtual WAN (vWAN) comes into play. Azure Virtual WAN is a networking service provided by Microsoft that offers a unified, globally distributed, and software-defined WAN solution. It simplifies network management, optimizes connectivity, enhances security, and provides the scalability required to meet the needs of modern businesses. Think of it as a network-as-a-service (NaaS) offering that abstracts away the complexities of managing a traditional WAN.

This tutorial provides a comprehensive introduction to Azure Virtual WAN, covering its key concepts, features, benefits, use cases, and a step-by-step guide to getting started. We’ll delve into the architecture, deployment models, and configuration options, empowering you to understand how vWAN can transform your network infrastructure.

1. Understanding Core Concepts of Azure Virtual WAN

Before diving into the practical aspects, let’s establish a firm understanding of the core concepts that underpin Azure Virtual WAN:

  • Virtual WAN Resource: This is the top-level resource in Azure that represents your entire Virtual WAN deployment. It’s a logical container for all other vWAN components. You manage your global network through this single resource.

  • Hub: A hub is a virtual network managed by Microsoft that acts as a central point of connectivity within a specific Azure region. It’s the core building block of your vWAN. Hubs contain various service gateways, such as VPN Gateway, ExpressRoute Gateway, Firewall, and more. These gateways provide connectivity to different network types (on-premises, other clouds, branch offices, etc.). Crucially, hubs within a Virtual WAN are automatically meshed. This means any resource connected to one hub can communicate with resources connected to any other hub in the same vWAN, without requiring complex manual routing configurations.

  • Sites (Branch Offices/On-Premises Locations): A site represents a physical location, such as a branch office, data center, or even a small remote office. You connect sites to your vWAN hubs using VPN or ExpressRoute connections.

  • Connections: A connection links a site (via a VPN or ExpressRoute circuit) to a hub’s gateway. Multiple connections can be established for redundancy and increased bandwidth.

  • Virtual Network Connection: This connects a standard Azure Virtual Network (VNet) to a vWAN hub. This allows resources within the VNet to leverage the connectivity and security features of the vWAN. Unlike a traditional VNet peering, connecting a VNet to a vWAN hub doesn’t require manual route configuration – the vWAN hub handles the routing automatically.

  • Routing: Azure Virtual WAN employs a sophisticated, dynamic routing system. It automatically learns routes from connected sites and VNets, and propagates them across the entire vWAN. This eliminates the need for complex manual routing configurations that are typical in traditional WAN deployments. You can influence routing using route tables and route maps, but the underlying system handles the complexities of route propagation and path selection.

  • Security: Security is integrated into the core of Azure Virtual WAN. You can deploy Azure Firewall within a hub (creating a “Secured Virtual Hub”) to centrally manage and enforce security policies for all traffic flowing through the vWAN. Integration with other Azure security services, like Azure DDoS Protection and Azure Web Application Firewall (WAF), further enhances security.

  • Hub-to-Hub Connectivity: As mentioned earlier, hubs within the same Virtual WAN are automatically connected. This full-mesh connectivity simplifies routing and ensures that any resource connected to any hub can communicate with any other resource in the vWAN.

  • Any-to-Any Connectivity: The combination of hub-to-hub connectivity and automatic route propagation enables any-to-any connectivity. This means any site, VNet, or user connected to the vWAN can communicate with any other connected entity, subject to security policies.

  • User VPN (Point-to-Site): Azure Virtual WAN supports User VPN connections, allowing individual users to securely connect to the vWAN from anywhere with an internet connection. This is ideal for remote workers or mobile users.

  • SD-WAN Integration: Azure Virtual WAN is designed to integrate seamlessly with various SD-WAN solutions from partners. This allows you to extend the benefits of your existing SD-WAN investments into the Azure cloud.

2. Key Benefits of Azure Virtual WAN

Adopting Azure Virtual WAN offers numerous advantages over traditional WAN solutions:

  • Simplified Management: vWAN provides a single pane of glass for managing your global network. The Azure portal and Azure Resource Manager (ARM) templates allow for centralized configuration, monitoring, and troubleshooting.

  • Global Connectivity: Leverage Microsoft’s global backbone network to connect your sites and users across the world with low latency and high reliability.

  • Scalability and Elasticity: vWAN scales automatically to meet your bandwidth and connectivity needs. You can easily add or remove sites and adjust capacity as your business requirements evolve.

  • Optimized Routing: The dynamic routing system in vWAN ensures optimal traffic flow and eliminates the need for complex manual routing configurations.

  • Integrated Security: Azure Firewall integration provides centralized security policy enforcement and protects your network from threats.

  • Cost Optimization: vWAN can help reduce costs by consolidating network infrastructure, optimizing bandwidth utilization, and eliminating the need for expensive dedicated circuits in some scenarios.

  • Hybrid Cloud Connectivity: Seamlessly connect your on-premises networks and other cloud environments to Azure.

  • SD-WAN Integration: Extend the benefits of your existing SD-WAN investments to Azure.

  • Improved User Experience: Low-latency connectivity and optimized routing improve the performance of applications and services for users, regardless of their location.

  • Faster Deployment: vWAN simplifies and accelerates the deployment of new sites and services.

3. Common Use Cases for Azure Virtual WAN

Azure Virtual WAN is a versatile solution that can address a wide range of networking scenarios:

  • Global Branch Connectivity: Connect branch offices around the world to Azure and to each other using VPN or ExpressRoute connections.

  • Hybrid Cloud Networking: Create a secure and reliable connection between your on-premises data centers and Azure.

  • Remote User Access: Enable secure remote access to Azure resources for employees working from home or on the go.

  • Multi-Cloud Connectivity: Connect your Azure environment to other cloud providers.

  • Disaster Recovery and Business Continuity: Use vWAN to build a resilient network infrastructure that can withstand outages and disruptions.

  • Application Modernization: Migrate applications to Azure and leverage vWAN to provide secure and reliable access for users.

  • IoT Connectivity: Connect IoT devices to Azure and manage them securely.

  • SD-WAN Extension: Integrate your existing SD-WAN solution with Azure to extend its benefits to the cloud.

4. Azure Virtual WAN Architecture and Deployment Models

Azure Virtual WAN offers flexibility in its deployment models, allowing you to choose the configuration that best suits your needs:

  • Basic Virtual WAN: This is the simplest deployment model, offering basic connectivity features. It’s suitable for scenarios where you only need VPN connectivity and don’t require advanced features like ExpressRoute or Azure Firewall integration. It does not support hub-to-hub connectivity.

  • Standard Virtual WAN: This is the most common deployment model, offering a full range of features, including VPN, ExpressRoute, User VPN, Azure Firewall integration, and hub-to-hub connectivity. It provides the most flexibility and scalability.

  • Secured Virtual Hub: This is a Standard Virtual WAN hub that has an Azure Firewall deployed within it. This provides centralized security policy enforcement for all traffic flowing through the hub. It’s the recommended approach for securing your vWAN.

Deployment Steps (Standard Virtual WAN with Secured Virtual Hub):

The following steps outline a typical deployment process for a Standard Virtual WAN with a Secured Virtual Hub:

  1. Create a Virtual WAN Resource:

    • In the Azure portal, search for “Virtual WANs” and select it.
    • Click “Create” to create a new Virtual WAN resource.
    • Provide a name, subscription, resource group, and location for the Virtual WAN.
    • Choose “Standard” for the Virtual WAN type.

  2. Create a Hub:

    • Within your Virtual WAN resource, click on “Hubs” and then “New Hub”.
    • Provide a name, region, and private IP address space for the hub. The address space should not overlap with any existing VNets or on-premises networks.
    • Select “Yes” for “Create a virtual hub firewall”. This will create a Secured Virtual Hub.

  3. Configure Azure Firewall:

    • Once the hub is created, you’ll be prompted to configure the Azure Firewall.
    • You can create firewall policies to define rules for inbound and outbound traffic. These policies control which traffic is allowed or denied based on source, destination, port, and protocol.

  4. Connect Sites (VPN or ExpressRoute):

    • To connect a site using VPN:
      • Click on “VPN sites” and then “Create VPN site”.
      • Provide a name, region, and device vendor/model for the VPN device at the site.
      • Enter the public IP address of the VPN device.
      • Create a connection between the VPN site and the hub.
    • To connect a site using ExpressRoute:
      • First, you need to provision an ExpressRoute circuit through a connectivity provider.
      • Once the circuit is provisioned, you can create an ExpressRoute gateway in the hub.
      • Create a connection between the ExpressRoute circuit and the ExpressRoute gateway.

  5. Connect Virtual Networks (VNets):

    • Click on “Virtual network connections” and then “Add connection”.
    • Select the VNet you want to connect to the hub.
    • The vWAN hub will automatically handle the routing between the VNet and other connected resources.

  6. Configure User VPN (Optional):

    • Click on “User VPN configurations” and then “Create user VPN configuration”.
    • Configure the authentication method (Azure Active Directory, RADIUS, or certificates).
    • Define the address pool for VPN clients.
    • Create a Point-to-Site gateway in the hub.
    • Download the VPN client configuration and install it on the user devices.

  7. Configure Routing (Optional):

    • While vWAN handles routing automatically, you can influence routing behavior using route tables and route maps.
    • You can create custom route tables and associate them with connections or VNets to override the default routing behavior.
    • Route maps allow you to filter and modify routes based on various criteria.

  8. Monitor and Troubleshoot:

    • Azure Monitor provides comprehensive monitoring capabilities for vWAN.
    • You can view metrics, logs, and alerts to monitor the health and performance of your network.
    • Azure Network Watcher provides tools for troubleshooting connectivity issues.

5. Step-by-Step Tutorial: Connecting a Branch Office with VPN

Let’s walk through a practical example of connecting a branch office to an Azure Virtual WAN using a VPN connection. This will illustrate the key steps involved in a real-world scenario.

Prerequisites:

  • An active Azure subscription.
  • A VPN device at the branch office that supports IKEv2 or IKEv1.
  • The public IP address of the branch office VPN device.
  • A pre-shared key (PSK) for the VPN connection.

Steps:

  1. Create a Virtual WAN Resource (if you haven’t already):

    • Follow the steps outlined in the “Deployment Steps” section above to create a Virtual WAN resource. Choose “Standard” as the type.

  2. Create a Hub (if you haven’t already):

    • Follow the steps in the “Deployment Steps” section to create a hub within your Virtual WAN resource. For this example, we’ll create a regular hub (not a Secured Virtual Hub).

  3. Create a VPN Site:

    • In the Azure portal, navigate to your Virtual WAN resource.
    • Click on “VPN sites” in the left-hand menu.
    • Click “+ Create VPN site”.
    • Basics Tab:
      • Region: Select the region where your branch office is located (or the closest Azure region).
      • Name: Enter a descriptive name for your branch office site (e.g., “BranchOffice-Seattle”).
      • Device Vendor: Select the vendor of your VPN device (e.g., Cisco, Fortinet, Check Point).
      • Device Model: Select the specific model of your VPN device. If your model isn’t listed, choose a generic option that supports IKEv2.
      • Private address space: (Optional). If you’re using BGP, enter the private IP address space of your on-premises network.
    • Links Tab:
      • Link Name: Enter a name for the VPN link (e.g., “Link-1”).
      • Link Speed: Enter the speed of your internet connection at the branch office.
      • Link Provider Name: Enter the name of your internet service provider.
      • Link IP Address: Enter the public IP address of your VPN device at the branch office.
      • Link BGP Address and ASN: (Optional). If you are using BGP for routing, enter appropriate BGP details.
      • Add New Link: (Optional). You can add multiple links for redundancy.
    • Click “Review + create” and then “Create”.

  4. Create a VPN Connection:

    • Go back to your Virtual WAN resource and click on “Hubs”.
    • Select the hub you created earlier.
    • Click on “VPN (Site to site)” in the left-hand menu.
    • Click “+ New VPN Connection”.
    • Basics Tab:
      • Connection Name: Enter a name for the connection (e.g., “Connection-to-BranchOffice”).
      • VPN Site: Select the VPN site you created in the previous step.
    • Settings Tab:
      • Pre-shared key (PSK): Enter a strong pre-shared key. This key must match the configuration on your branch office VPN device.
      • IKE Protocol: Select IKEv2 (recommended) or IKEv1.
      • IPSec/IKE policy: You can choose Default or Custom. Default uses pre-configured settings, while Custom gives you more fine-grained control over encryption and authentication algorithms. For simplicity, choose Default for this tutorial.
      • Use policy based traffic selector: Enable this if your on-premise VPN device uses policy-based traffic selectors.
      • Enable BGP: (Optional). Enable this if you’re using BGP for routing.
    • Click “Review + create” and then “Create”.

  5. Configure the VPN Device at the Branch Office:

    • This step varies depending on the specific VPN device you are using. You will need to configure the following settings on your device:
      • Connection Type: Site-to-Site VPN.
      • Remote Gateway/Peer IP Address: This is the public IP address of the VPN gateway in your Azure Virtual WAN hub. You can find this in the Azure portal under your hub’s VPN (Site to site) settings. There will be two instance IP addresses, for redundancy. You should configure both on your on-premises device, if supported.
      • Local Network: The private IP address range of your branch office network.
      • Remote Network: The private IP address range of your Azure Virtual WAN hub.
      • Pre-shared Key (PSK): Enter the same pre-shared key you configured in the Azure portal.
      • IKE Protocol: Match the protocol you selected in Azure (IKEv2 or IKEv1).
      • IPSec/IKE Policy: Match the settings you selected in Azure (or use equivalent settings if your device doesn’t have the exact same options).
      • Traffic Selectors (if using policy based VPN). You will need to specify the on-premise network and hub address space.

  6. Verify Connectivity:

    • Once the VPN connection is established, you should be able to ping resources in your Azure Virtual WAN hub from your branch office network, and vice-versa.
    • You can also check the connection status in the Azure portal.

6. Connecting a Virtual Network (VNet) to the Hub

After connecting your branch office, you’ll likely want to connect Azure Virtual Networks (VNets) to your hub so that resources in those VNets can communicate with your on-premises network.

  1. Navigate to the Hub:

    • In the Azure portal, go to your Virtual WAN resource and select the hub.

  2. Create a Virtual Network Connection:

    • Click on “Virtual network connections” in the left-hand menu.
    • Click “+ Add connection”.
    • Connection Name: Enter a name for the connection (e.g., “Connection-to-MyVNet”).
    • Subscription: Select the subscription containing the VNet.
    • Resource group: Select the resource group containing the VNet.
    • Virtual network: Select the VNet you want to connect.
    • Propagate to none: (Optional) if you select “Yes,” no routes from this connection will be propagated.
    • Click “Create”.

Azure Virtual WAN will automatically handle the routing between the connected VNet and the hub, as well as any other connected sites or VNets. You don’t need to configure VNet peering or user-defined routes (UDRs) manually.

7. Security Considerations and Azure Firewall Integration

Security is paramount in any network deployment. Azure Virtual WAN offers robust security features, primarily through integration with Azure Firewall.

  • Secured Virtual Hub: As mentioned earlier, a Secured Virtual Hub is a hub with an Azure Firewall deployed within it. This is the recommended approach for securing your vWAN.

  • Azure Firewall Policies: You create firewall policies to define rules that control traffic flow through the firewall. These rules specify allowed or denied traffic based on:

    • Source: IP addresses, IP ranges, or service tags.
    • Destination: IP addresses, IP ranges, or service tags.
    • Ports: Specific ports or port ranges.
    • Protocols: TCP, UDP, ICMP, etc.
    • Application Rules (FQDNs): You can allow or deny traffic based on fully qualified domain names (FQDNs). This requires configuring DNS settings in the firewall.

  • Network Rules: These rules control traffic based on IP addresses, ports, and protocols.

  • Application Rules: These rules control traffic based on FQDNs.

  • Threat Intelligence: Azure Firewall can use threat intelligence feeds from Microsoft to automatically block traffic from known malicious IP addresses and domains.

  • Forced Tunneling: You can configure forced tunneling to route all internet-bound traffic from your VNets through the Azure Firewall in your Secured Virtual Hub. This ensures that all outbound traffic is inspected and filtered.

Example: Creating a Firewall Policy:

  1. Navigate to Azure Firewall Manager:

    • In the Azure portal, search for “Firewall Manager” and select it.

  2. Create a Firewall Policy:

    • Click on “Azure Firewall Policies” and then “+ Create Azure Firewall Policy”.
    • Basics Tab:
      • Policy Tier: Choose “Standard” or “Premium” (Premium offers additional features like IDPS and TLS inspection).
      • Region: Select the region where your Secured Virtual Hub is located.
      • Name: Enter a name for the policy.
    • DNS Settings (Optional): Configure DNS settings if you want to use application rules with FQDNs.
    • Rules Tab:
      • Click “+ Add a rule collection”.
      • Rule Collection Type: Choose “Network rule collection” or “Application rule collection”.
      • Name: Enter a name for the rule collection.
      • Priority: Enter a priority for the rule collection (lower numbers have higher priority).
      • Click “+ Add rule”.
        • Name: Enter a name for the rule.
        • Source Type: Select IP addresses, IP Groups, or Service Tags.
        • Source: Enter the source IP addresses, IP ranges, or service tags.
        • Destination Type: Select IP addresses, IP Groups, or Service Tags (or FQDNs for application rules).
        • Destination: Enter the destination IP addresses, IP ranges, service tags, or FQDNs.
        • Ports: Enter the ports or port ranges.
        • Protocol: Select the protocol (TCP, UDP, ICMP, etc.).
        • Action: Select “Allow” or “Deny”.
    • Click “Review + create” and then “Create”.

  3. Associate the Policy with Your Secured Virtual Hub:

    • Go to your Secured Virtual Hub in the Azure portal.
    • Click on “Azure Firewall Manager”.
    • Select the “Azure Firewall policies” tab.
    • Select the firewall policy you created and click “Save”.

8. Advanced Topics and Considerations

  • BGP (Border Gateway Protocol): Azure Virtual WAN supports BGP for dynamic routing with on-premises networks. BGP allows your on-premises routers to exchange routing information with the Azure Virtual WAN hub, enabling automatic route propagation and failover.

  • Route Maps: Route maps provide advanced control over route filtering and modification. You can use them to influence routing decisions based on various criteria, such as AS path, community strings, and prefixes.

  • Custom Routing: While vWAN handles most routing automatically, you can use custom route tables to override the default behavior.

  • Monitoring and Troubleshooting: Utilize Azure Monitor and Azure Network Watcher for comprehensive monitoring and troubleshooting of your vWAN deployment.

  • Cost Management: Understand the pricing model for Azure Virtual WAN and optimize your deployment to minimize costs. Consider factors like data transfer charges, gateway usage, and firewall usage.

  • ExpressRoute and VPN Gateway Scaling. Understand the scaling capabilities of both ExpressRoute and VPN Gateways. Multiple connections, active-active gateways, and BGP can be used to increase bandwidth and resilience.

  • Global Transit Network Architecture. vWAN can be used as the foundation for a global transit network, connecting multiple Azure regions, on-premises locations, and even other cloud providers.

  • Integration with other Azure services: vWAN integrates with various other Azure services, such as Azure Front Door, Azure Traffic Manager, and Azure Private Link, enabling you to build complex and highly available network architectures.

Conclusion: Embracing the Future of WAN with Azure

Azure Virtual WAN represents a significant advancement in wide area networking. It provides a modern, cloud-native solution that addresses the challenges of traditional WANs and empowers businesses to build a global, secure, and scalable network infrastructure. By understanding the core concepts, benefits, and deployment models of vWAN, you can leverage its capabilities to transform your network and accelerate your cloud journey. This tutorial has provided a comprehensive introduction, but the best way to truly understand vWAN is to experiment with it in your own Azure environment. Start with a small-scale deployment and gradually expand as you become more familiar with the service. The journey to a modern, agile, and cloud-optimized WAN starts with Azure Virtual WAN.

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