A Guide to Azure Data Transfer Pricing
Understanding Azure networking charges is essential for businesses aiming to manage their budgets effectively. Given the complexity of Azure networking pricing, which involves various influencing factors, the goal here is to bring a clearer understanding of the associated data transfer costs by breaking down the pricing models into the following use cases: VM to VM VM to Private Endpoint VM to Internal Standard Load Balancer (ILB) VM to Internet Hybrid connectivity Please note this is a first version, with a second version to follow that will include additional scenarios. Disclaimer: Pricing may change over time, check the public Azure pricing calculator for up-to-date pricing information. Actual pricing may vary depending on agreements, purchase dates, and currency exchange rates. Sign in to the Azure pricing calculator to see pricing based on your current program/offer with Microsoft. 1. VM to VM 1.1. VM to VM, same VNet Data transfer within the same virtual network (VNet) is free of charge. This means that traffic between VMs within the same VNet will not incur any additional costs. Doc. Data transfer across Availability Zones (AZ) is free. Doc. 1.2. VM to VM, across VNet peering Azure VNet peering enables seamless connectivity between two virtual networks, allowing resources in different VNets to communicate with each other as if they were within the same network. When data is transferred between VNets, charges apply for both ingress and egress data. Doc: VM to VM, across VNet peering, same region VM to VM, across Global VNet peering Azure regions are grouped into 3 Zones (distinct from Avaialbility Zones within a specific Azure region). The pricing for Global VNet Peering is based on that geographic structure. Data transfer between VNets in different zones incurs outbound and inbound data transfer rates for the respective zones. When data is transferred from a VNet in Zone 1 to a VNet in Zone 2, outbound data transfer rates for Zone 1 and inbound data transfer rates for Zone 2 will be applicable. Doc. 1.3. VM to VM, through Network Virtual Appliance (NVA) Data transfer through an NVA involves charges for both ingress and egress data, depending on the volume of data processed. When an NVA is in the path, such as for spoke VNet to spoke VNet connectivity via an NVA (firewall...) in the hub VNet, it incurs VM to VM pricing twice. The table above reflects only data transfer charges and does not include NVA/Azure Firewall processing costs. 2. VM to Private Endpoint (PE) Private Endpoint pricing includes charges for the provisioned resource and data transfer costs based on traffic direction. For instance, writing to a Storage Account through a Private Endpoint incurs outbound data charges, while reading incurs inbound data charges. Doc: 2.1. VM to PE, same VNet Since data transfer within a VNet is free, charges are only applied for data processing through the Private Endpoint. Cross-region traffic will incur additional costs if the Storage Account and the Private Endpoint are located in different regions. 2.2. VM to PE, across VNet peering Accessing Private Endpoints from a peered network incurs only Private Link Premium charges, with no peering fees. Doc. VM to PE, across VNet peering, same region VM to PE, across VNet peering, PE region != SA region 2.3. VM to PE, through NVA When an NVA is in the path, such as for spoke VNet to spoke VNet connectivity via a firewall in the hub VNet, it incurs VM to VM charges between the VM and the NVA. However, as per the PE pricing model, there are no charges between the NVA and the PE. The table above reflects only data transfer charges and does not include NVA/Azure Firewall processing costs. 3. VM to Internal Load Balancer (ILB) Azure Standard Load Balancer pricing is based on the number of load balancing rules as well as the volume of data processed. Doc: 3.1. VM to ILB, same VNet Data transfer within the same virtual network (VNet) is free. However, the data processed by the ILB is charged based on its volume and on the number load balancing rules implemented. Only the inbound traffic is processed by the ILB (and charged), the return traffic goes direct from the backend to the source VM (free of charge). 3.2. VM to ILB, across VNet peering In addition to the Load Balancer costs, data transfer charges between VNets apply for both ingress and egress. 3.3. VM to ILB, through NVA When an NVA is in the path, such as for spoke VNet to spoke VNet connectivity via a firewall in the hub VNet, it incurs VM to VM charges between the VM and the NVA and VM to ILB charges between the NVA and the ILB/backend resource. The table above reflects only data transfer charges and does not include NVA/Azure Firewall processing costs. 4. VM to internet 4.1. Data transfer and inter-region pricing model Bandwidth refers to data moving in and out of Azure data centers, as well as data moving between Azure data centers; other transfers are explicitly covered by the Content Delivery Network, ExpressRoute pricing, or Peering. Doc: 4.2. Routing Preference in Azure and internet egress pricing model When creating a public IP in Azure, Azure Routing Preference allows you to choose how your traffic routes between Azure and the Internet. You can select either the Microsoft Global Network or the public internet for routing your traffic. Doc: See how this choice can impact the performance and reliability of network traffic: By selecting a Routing Preference set to Microsoft network, ingress traffic enters the Microsoft network closest to the user, and egress traffic exits the network closest to the user, minimizing travel on the public internet (“Cold Potato” routing). On the contrary, setting the Routing Preference to internet, ingress traffic enters the Microsoft network closest to the hosted service region. Transit ISP networks are used to route traffic, travel on the Microsoft Global Network is minimized (“Hot Potato” routing). Bandwidth pricing for internet egress, Doc: 4.3. VM to internet, direct Data transferred out of Azure to the internet incurs charges, while data transferred into Azure is free of charge. Doc. It is important to note that default outbound access for VMs in Azure will be retired on September 30 2025, migration to an explicit outbound internet connectivity method is recommended. Doc. 4.4. VM to internet, with a public IP Here a standard public IP is explicitly associated to a VM NIC, that incurs additional costs. Like in the previous scenario, data transferred out of Azure to the internet incurs charges, while data transferred into Azure is free of charge. Doc. 4.5. VM to internet, with NAT Gateway In addition to the previous costs, data transfer through a NAT Gateway involves charges for both the data processed and the NAT Gateway itself, Doc: 5. Hybrid connectivity Hybrid connectivity involves connecting on-premises networks to Azure VNets. The pricing model includes charges for data transfer between the on-premises network and Azure, as well as any additional costs for using Network Virtual Appliances (NVAs) or Azure Firewalls in the hub VNet. 5.1. H&S Hybrid connectivity without firewall inspection in the hub For an inbound flow, from the ExpressRoute Gateway to a spoke VNet, VNet peering charges are applied once on the spoke inbound. There are no charges on the hub outbound. For an outbound flow, from a spoke VNet to an ER branch, VNet peering charges are applied once, outbound of the spoke only. There are no charges on the hub inbound. Doc. The table above does not include ExpressRoute connectivity related costs. 5.2. H&S Hybrid connectivity with firewall inspection in the hub Since traffic transits and is inspected via a firewall in the hub VNet (Azure Firewall or 3P firewall NVA), the previous concepts do not apply. “Standard” inter-VNet VM-to-VM charges apply between the FW and the destination VM : inbound and outbound on both directions. Once outbound from the source VNet (Hub or Spoke), once inbound on the destination VNet (Spoke or Hub). The table above reflects only data transfer charges within Azure and does not include NVA/Azure Firewall processing costs nor the costs related to ExpressRoute connectivity. 5.3. H&S Hybrid connectivity via a 3rd party connectivity NVA (SDWAN or IPSec) Standard inter-VNet VM-to-VM charges apply between the NVA and the destination VM: inbound and outbound on both directions, both in the Hub VNet and in the Spoke VNet. 5.4. vWAN scenarios VNet peering is charged only from the point of view of the spoke – see examples and vWAN pricing components. Next steps with cost management To optimize cost management, Azure offers tools for monitoring and analyzing network charges. Azure Cost Management and Billing allows you to track and allocate costs across various services and resources, ensuring transparency and control over your expenses. By leveraging these tools, businesses can gain a deeper understanding of their network costs and make informed decisions to optimize their Azure spending.
How to migrate an existing Standard Azure Firewall to Premium
Migrate an existing Standard SKU Azure Firewall to Premium SKU If you have an existing Azure Standard Firewall and are looking to move forward with upgrading it to Azure Premium Firewall to take advantage of the advanced features like TLS Inspection, Threat Intelligence, and URL filtering, supported with Azure Firewall Premium and are also looking to use the existing Public IP and VNET configuration, then this post is for you! Use Case: This can be used when there is an existing Standard SKU Azure Firewall with a single Public IP and if you might want to upgrade the existing Standard SKU Azure Firewall to a Premium SKU Azure Firewall. This can be done currently using Azure PowerShell only. This can either be done using Azure Cloud Shell in PowerShell mode or from Azure PowerShell. If Azure PowerShell is being used, the minimum required version of the Azure PowerShell module is 6.5.0. Please refer Az 6.5.0 . This blog talks about the steps to be done on the currently existing Standard SKU Azure Firewall, using the stop/start method using Azure PowerShell, which deallocates or removes the Public IP associated with the Azure Firewall (stop operation) to then re-attach the Public IP (start operation) with the upgraded Azure Firewall. Downtime Consideration: Please be aware that this is involving deallocating and allocating the Azure Firewall so we recommend performing this migration during a planned maintenance window as stop and start operation takes some time. Please refer https://docs.microsoft.com/en-us/azure/firewall/premium-migrate#downtime Steps to deallocate the Standard Azure Firewall: In order to deallocate the Standard Azure Firewall, please follow these steps using Azure PowerShell. Please use the below command to set the correct subscription ID of the subscription where the existing Standard Azure Firewall is deployed. Set-AzContext "<Subscription ID>" We need the following inputs for running the Azure PowerShell commands to perform the stop operation. Example: Firewall Name = Test-FW01 Firewall resource group name = Test-FW-RG This command is used to get the Firewall configuration in the $azfw variable. $azfw = Get-AzFirewall -Name "<firewall-name>" -ResourceGroupName "<resource-group-name>" The below method is used to deallocate the Azure Standard Firewall which is nothing but stopping the existing Standard Azure Firewall and removing the Public IP associated with it, the end of running the below command, you can see the Public IP will be successfully detached from the existing standard SKU Azure Firewall. $azfw.Deallocate() The below command is used to save the updated configuration changes to the Azure Firewall. Set-AzFirewall -AzureFirewall $azfw To check if Azure Firewall has been stopped and is deallocated: To validate if deallocation is complete, you can go to the Azure Portal and navigate to the Azure Firewall resource, and to the Overview Page, under the Provisioning state, you will notice that the Azure Standard Firewall shows that it is in the "Succeeded" state after stop operation is complete and also you will find that the Public IP is not seen listed under the Public IP settings of Azure Firewall resource. Steps to upgrade the Standard Azure Firewall to Premium SKU and update the Azure Premium Firewall with the same public IP: With the deallocate operation complete, now we have to upgrade the existing Standard Azure Firewall to Premium SKU, with a start operation which can also be currently performed, only using Azure PowerShell, to allocate the Standard SKU Azure Firewall with the same public IP and upgrade the SKU to Premium SKU. Inputs Needed: Firewall name = Name of the Standard SKU Azure Firewall that exists Resource-group-name = Name of the resource group where the Standard SKU Azure Firewall is deployed $azfw = Existing Standard SKU Azure Firewall configuration $vnet = VNET configuration of the existing Standard SKU Azure Firewall. $publicip = Public IP associated with the Standard SKU Azure Firewall. This command below is used to get the existing Standard Azure Firewall configuration in the $azfw variable. $azfw = Get-AzFirewall -Name "<firewall-name>" -ResourceGroupName "<resource-group-name>" Setting the $azfw variable, please run the below command, which is used to upgrade the SKU tier of the existing Standard SKU Firewall to Premium. $azfw.Sku.Tier="Premium" With the migration to Premium SKU complete for the Standard Azure Firewall, running this command below will get the Virtual network configuration of the existing Standard SKU Azure Firewall into the $vnet variable. $vnet = Get-AzVirtualNetwork -ResourceGroupName "<resource-group-name>" -Name "<Virtual-Network-Name>" Then, this command below will fetch the Public IP Address configuration that is associated with the existing Standard SKU Azure Firewall and save it in the variable $publicip for using it. $publicip = Get-AzPublicIpAddress -Name "<Firewall-PublicIP-name>" -ResourceGroupName "<resource-group-name>" After completing the above steps to set the variables, this step below is used to allocate the existing Public IP that was associated with the Standard SKU Azure Firewall and also the VNET configuration pre-fetched using variables $publicip and $vnet respectively, in the previous steps, to use it to attach to the new Azure Premium Firewall. $azfw.Allocate($vnet,$publicip) The below step is to make sure the updated changes are saved to the Azure Firewall Premium successfully. Set-AzFirewall -AzureFirewall $azfw End of performing the above steps, you will see that the Standard Azure Firewall has been successfully upgraded to Premium SKU with the same Public IP. To check if Azure Firewall has been upgraded to Premium SKU after being started and is allocated with the same public IP: To validate if the allocation is complete, you can go to the Azure Portal and navigate to the Azure Firewall resource, and to the Overview Page, under the Provisioning state, you will notice that the Azure Standard Firewall shows that it is in the "Succeeded" state after the start operation is complete, under SKU, you can see that it is "Premium" and also you will find that the Public IP is seen listed under the Public IP settings of Azure Firewall Premium resource that shows the allocation of the same Public IP succeeded. Note: TLS Inspection and other related features with Azure Firewall Premium will have to be enabled manually using Azure Portal or Azure PowerShell, or related supported methods as that will not be automatically enabled with upgrading the Azure Standard Firewall to Azure Premium Firewall. This will not upgrade Azure Standard Firewall Policy and for upgrading Standard Firewall Policy to Azure Premium Firewall Policy, please use this ready run PowerShell script, Migration script to upgrade Azure Standard Firewall Policy to Premium . Also, the necessary Powershell modules like Az. Resources, Az.Network and Az. Account has to be installed with the latest version available as per Az 6.5.0, if Azure PowerShell is chosen as the preferred method to implement the migration instead of Azure Cloud Shell in PowerShell mode. Hope this post was insightful! Happy Learning!
Controlling Data Egress in Azure
Regulated companies impose stringent requirements on data governance to prevent data exfiltration. As a Cloud Architect, ensuring the safe and efficient exit of data from our network to external destinations is paramount. This document aims to provide a comprehensive guide to the strategies, best practices, and tools we employ at various customers to maintain robust security measures.Combining firewall protection and SD-WAN connectivity in Azure virtual WAN
Virtual WAN (vWAN) introduces new security and connectivity features in Azure, including the ability to operate managed third-party firewalls and SD-WAN virtual appliances, integrated natively within a virtual WAN hub (vhub). This article will discuss updated network designs resulting from these integrations and examine how to combine firewall protection and SD-WAN connectivity when using vWAN. The objective is not to delve into the specifics of the security or SD-WAN connectivity solutions, but to provide an overview of the possibilities. Firewall protection in vWAN In a vWAN environment, the firewall solution is deployed either automatically inside the vhub (Routing Intent) or manually in a transit VNet (VM-series deployment). Routing Intent (managed firewall) Routing Intent refers to the concept of implementing a managed firewall solution within the vhub for internet protection or private traffic protection (VNet-to-VNet, Branch-to-VNet, Branch-to-Branch), or both. The firewall could be either an Azure Firewall or a third-party firewall, deployed within the vhub as Network Virtual Appliances or a SaaS solution. A vhub containing a managed firewall is called a secured hub. For an updated list of Routing Intent supported third-party solutions please refer to the following links: managed NVAs SaaS solution Transit VNet (unmanaged firewall) Another way to provide inspection in vWAN is to manually deploy the firewall solution in a spoke of the vhub and to cascade the actual spokes behind that transit firewall VNet (aka indirect spoke model or tiered-VNet design). In this discussion, the primary reasons for choosing unmanaged deployments are: either the firewall solution lacks an integrated vWAN offer, or it has an integrated offer but falls short in horizontal scalability or specific features compared to the VM-based version. For a detailed analysis on the pros and cons of each design please refer to this article. SD-WAN connectivity in vWAN Similar to the firewall deployment options, there are two main methods for extending an SDWAN overlay into an Azure vWAN environment: a managed deployment within the vhub, or a standard VM-series deployment in a spoke of the vhub. More options here. SD-WAN in vWAN deployment (managed) In this scenario, a pair of virtual SD-WAN appliances are automatically deployed and integrated in the vhub using dynamic routing (BGP) with the vhub router. Deployment and management processes are streamlined as these appliances are seamlessly provisioned in Azure and set up for a simple import into the partner portal (SD-WAN orchestrator). For an updated list of supported SDWAN partners please refer to this link. For more information on SD-WAN in vWAN deployments please refer to this article. VM-series deployment (unmanaged) This solution requires manual deployment of the virtual SD-WAN appliances in a spoke of the vhub. The underlying VMs and the horizontal scaling are managed by the customer. Dynamic route exchange with the vWAN environment is achieved leveraging BGP peering with the vhub. Alternatively, and depending on the complexity of your addressing plan, static routing may also be possible. Firewall protection and SD-WAN in vWAN THE CHALLENGE! Currently, it is only possible to chain managed third-party SD-WAN connectivity with Azure Firewall in the same vhub, or to use dual-role SD-WAN connectivity and security appliances. Routing Intent provided by third-party firewalls combined with another managed SD-WAN solution inside the same vhub is not yet supported. But how can firewall protection and SD-WAN connectivity be integrated together within vWAN? Solution 1: Routing Intent with Azure Firewall and managed SD-WAN (same vhub) Firewall solution: managed. SD-WAN solution: managed. This design is only compatible with Routing Intent using Azure Firewall, as it is the sole firewall solution that can be combined with a managed SD-WAN in vWAN deployment in that same vhub. With the private traffic protection policy enabled in Routing Intent, all East-West flows (VNet-to-VNet, Branch-to-VNet, Branch-to-Branch) are inspected. Solution 2: Routing Intent with a third-party firewall and managed SD-WAN (2 vhubs) Firewall solution: managed. SD-WAN solution: managed. To have both a third-party firewall managed solution in vWAN and an SD-WAN managed solution in vWAN in the same region, the only option is to have a vhub dedicated to the security solution deployment and another vhub dedicated to the SD-WAN solution deployment. In each region, spoke VNets are connected to the secured vhub, while SD-WAN branches are connected to the vhub containing the SD-WAN deployment. In this design, Routing Intent private traffic protection provides VNet-to-VNet and Branch-to-VNet inspection. However, Branch-to-Branch traffic will not be inspected. Solution 3: Routing Intent and SD-WAN spoke VNet (same vhub) Firewall solution: managed. SD-WAN solution: unmanaged. This design is compatible with any Routing Intent supported firewall solution (Azure Firewall or third-party) and with any SD-WAN solution. With Routing Intent private traffic protection enabled, all East-West flows (VNet-to-VNet, Branch-to-VNet, Branch-to-Branch) are inspected. Solution 4: Transit firewall VNet and managed SDWAN (same vhub) Firewall solution: unmanaged. SD-WAN solution: managed. This design utilizes the indirect spoke model, enabling the deployment of managed SD-WAN in vWAN appliances. This design provides VNet-to-VNet and Branch-to-VNet inspection. But because the firewall solution is not hosted in the hub, Branch-to-Branch traffic will not be inspected. Solution 5 - Transit firewall VNet and SD-WAN spoke VNet (same vhub) Firewall solution: unmanaged. SD-WAN solution: unmanaged. This design integrates both the security and the SD-WAN connectivity as unmanaged solutions, placing the responsibility for deploying and managing the firewall and the SD-WAN hub on the customer. Just like in solution #4, only VNet-to-VNet and Branch-to-VNet traffic is inspected. Conclusion Although it is currently not possible to combine a managed third-party firewall solution with a managed SDWAN deployment within the same vhub, numerous design options are still available to meet various needs, whether managed or unmanaged approaches are preferred.Introducing Copilot in Azure for Networking: Your AI-Powered Azure Networking Assistant
As cloud networking grows in complexity, managing and operating these services efficiently can be tedious and time consuming. That’s where Copilot in Azure for Networking steps in, a generative AI tool that simplifies every aspect of network management, making it easier for network administrators to stay on top of their Azure infrastructure. With Copilot, network professionals can design, deploy, and troubleshoot Azure Networking services using a streamlined, AI-powered approach. A Comprehensive Networking Assistant for Azure We’ve designed Copilot to really feel like an intuitive assistant you can talk to just like a colleague. Copilot understands networking-related questions in simple terms and responds with actionable solutions, drawing from Microsoft’s expansive networking knowledge base and the specifics of your unique Azure environment. Think of Copilot as an all-encompassing AI-Powered Azure Networking Assistant. It acts as: Your Cloud Networking Specialist by quickly answering questions about Azure networking services, providing product guidance, and configuration suggestions. Your Cloud Network Architect by helping you select the right network services, architectures, and patterns to connect, secure, and scale your workloads in Azure. Your Cloud Network Engineer by helping you diagnose and troubleshoot network connectivity issues with step-by-step guidance. One of the most powerful features of Copilot in Azure is its ability to automatically diagnose common networking issues. Misconfigurations, connectivity failures, or degraded performance? Copilot can help with step-by-step guidance to resolve these issues quickly with minimal input and assistance from the user, simply ask questions like ”Why can’t my VM connect to the internet?”. As seen above, upon the user identifying the source and destination, Copilot can automatically discover the connectivity path and analyze the state and status of all the network elements in the path to pinpoint issues such as blocked ports, unhealthy network devices, or misconfigured Network Security Groups (NSGs). Technical Deep Dive: Contextualized Responses with Real-Time Insights When users ask a question on the Azure Portal, it gets sent to the Orchestrator. This step is crucial to generating a deep semantic understanding of the user’s question, reasoning over all Azure resources, and then determining that the question requires Network-specific capabilities to be answered. Copilot then collects contextual information based on what the user is looking at and what they have access to before dispatching the question to the relevant domain-specific plugins. Those plugins then use their service-specific capabilities to answer the user’s question. Copilot may even combine information from multiple plugins to provide responses to complex questions. In the case of questions relevant to Azure Networking services, Copilot uses real-time data from sources like diagnostic APIs, user logs, Azure metrics, Azure Resource Graph etc. all while maintaining complete privacy and security and only accessing what the user can access as defined in Azure Role based Access Control (RBAC) to help generate data-driven insights that help keep your network operating smoothly and securely. This information is then used by Copilot to help answer the user’s question via a variety of techniques including but not limited to Retrieval-Augmented Generation (RAG) and grounding. To learn more about how Copilot works, including our Responsible AI commitments, see Copilot in Azure Technical Deep Dive | Microsoft Community Hub. Summary: Key Benefits, Capabilities and Sample Prompts Copilot boosts efficiency by automating routine tasks and offering targeted answers, which saves network administrators time while troubleshooting, configuring and architecting their environments. Copilot also helps organizations reduce costs by minimizing manual work and catching errors while empowering customers to resolve networking issues on their own with AI-powered insights backed by Azure expertise. Copilot is equipped with powerful skills to assist users with network product information and selection, resource inventory and topology, and troubleshooting. For product information, Copilot can answer questions about Azure Networking products by leveraging published documentation, helping users with questions like “What type of Firewall is best suited for my environment?”. It offers tailored guidance for selecting and planning network architectures, including specific services like Azure Load Balancer and Azure Firewall. This guidance also extends to resilience-related questions like “What more can I do to ensure my app gateway is resilient?” involving services such as Azure Application Gateway and Azure Traffic Manager, among others. When it comes to inventory and topology, Copilot can help with questions like “What is the data path between my VM and the internet?” by mapping network resources, visualizing topologies, and tracking traffic paths, providing users with clear topology maps and connectivity graphs. For troubleshooting questions like “Why can’t I connect to my VM from on prem?”, Copilot analyzes both the control plane and data plane, offering diagnostics at the network and individual service levels. By using on-behalf-of RBAC, Copilot maintains secure, authorized access, ensuring users interact only with resources permitted by their access level. Looking Forward: Future Enhancements This is only the first step we are taking toward bringing interactive, generative-AI powered capabilities to Azure Networking services and as it evolves over time, future releases will introduce advanced capabilities. We also acknowledge that today Copilot in preview works better with certain Azure Networking services, and we will continue to onboard more services to the capabilities we are launching today. Some of the more advanced capabilities we are working on include predictive troubleshooting where Copilot will anticipate potential issues before they impact network performance. Network optimization capabilities that suggest ways to optimize your network for better performance, resilience and reliability alongside enhanced security capabilities providing insights into network security and compliance, helping organizations meet regulatory requirements starting with the integration of Security Copilot attack investigation capabilities for Azure Firewall. Conclusion Copilot in Azure for Networking is intended to enhance the overall Azure experience and help network administrators easily manage their Azure Networking services. By combining AI-driven insights with user-friendly interfaces, it empowers networking professionals and users to plan, deploy, and operate their Azure Network. These capabilities are now in preview, see Azure networking capabilities using Microsoft Copilot in Azure (preview) | Microsoft Learn to learn more and get started.Inspection Patterns in Hub-and-Spoke and vWAN Architectures
By shruthi_nair Mays_Algebary Inspection plays a vital role in network architecture, and each customer may have unique inspection requirements. This article explores common inspection scenarios in both Hub-and-Spoke and Virtual WAN (vWAN) topologies. We’ll walk through design approaches assuming a setup with two Hubs or Virtual Hubs (VHubs) connected to on-premises environments via ExpressRoute. The specific regions of the Hubs or VHubs are not critical, as the same design principles can be applied across regions. Scenario1: Hub-and-Spoke Inspection Patterns In the Hub-and-Spoke scenarios, the baseline architecture assumes the presence of two Hub VNets. Each Hub VNet is peered with its local spoke VNets as well as with the other Hub VNet (Hub2-VNet). Additionally, both Hub VNets are connected to both local and remote ExpressRoute circuits to ensure redundancy. Note: In Hub-and-Spoke scenarios, connectivity between virtual networks over ExpressRoute circuits across Hubs is intentionally disabled. This ensures that inter-Hub traffic uses VNet peering, which provides a more optimized path, rather than traversing the ExpressRoute circuit. In Scenario 1, we present two implementation approaches: a traditional method and an alternative leveraging Azure Virtual Network Manager (AVNM). Option1: Full Inspection A widely adopted design pattern is to inspect all traffic, both east-west and north-south, to meet security and compliance requirements. This can be implemented using a traditional Hub-and-Spoke topology with VNet Peering and User-Defined Routes (UDRs), or by leveraging AVNM with Connectivity Configurations and centralized UDR management. In the traditional approach: VNet Peering is used to connect each spoke to its local Hub, and to establish connectivity between the two Hubs. UDRs direct traffic to the firewall as the next hop, ensuring inspection before reaching its destination. These UDRs are applied at the Spoke VNets, the Gateway Subnet, and the Firewall Subnet (especially for inter-region scenarios), as shown in the below diagram. As your environment grows, managing individual UDRs and VNet Peerings manually can become complex. To simplify deployment and ongoing management at scale, you can use AVNM. With AVNM: Use the Hub-and-Spoke connectivity configuration to manage routing within a single Hub. Use the Mesh connectivity configuration to establish Inter-Hub connectivity between the two Hubs. AVNM also enables centralized creation, assignment, and management of UDRs, streamlining network configuration at scale. Connectivity Inspection Table Connectivity Scenario Inspected On-premises ↔ Azure ✅ Spoke ↔ Spoke ✅ Spoke ↔ Internet ✅ Option2: Selective Inspection Between Azure VNets In some scenarios, full traffic inspection is not required or desirable. This may be due to network segmentation based on trust zones, for example, traffic between trusted VNets may not require inspection. Other reasons include high-volume data replication, latency-sensitive applications, or the need to reduce inspection overhead and cost. In this design, VNets are grouped into trusted and untrusted zones. Trusted VNets can exist within the same Hub or across different Hubs. To bypass inspection between trusted VNets, you can connect them directly using VNet Peering or AVNM Mesh connectivity topology. It’s important to note that UDRs are still used and configured as described in the full inspection model (Option 1). However, when trusted VNets are directly connected, system routes (created by VNet Peering or Mesh connectivity) take precedence over custom UDRs. As a result, traffic between trusted VNets bypasses the firewall and flows directly. In contrast, traffic to or from untrusted zones follows the UDRs, ensuring it is routed through the firewall for inspection. t Connectivity Inspection Table Connectivity Scenario Inspected On-premises ↔ Azure ✅ Spoke ↔ Internet ✅ Spoke ↔ Spoke (Same Zones) ❌ Spoke ↔ Spoke (Across Zones) ✅ Option3: No Inspection to On-premises In cases where a firewall at the on-premises or colocation site already inspects traffic from Azure, customers typically aim to avoid double inspection. To support this in the above design, traffic destined for on-premises is not routed through the firewall deployed in Azure. For the UDRs applied to the spoke VNets, ensure that "Propagate Gateway Routes" is set to true, allowing traffic to follow the ExpressRoute path directly without additional inspection in Azure. Connectivity Inspection Table Connectivity Scenario Inspected On-premises ↔ Azure ❌ Spoke ↔ Spoke ✅ Spoke ↔ Internet ✅ Option4: Internet Inspection Only While not generally recommended, some customers choose to inspect only internet-bound traffic and allow private traffic to flow without inspection. In such cases, spoke VNets can be directly connected using VNet Peering or AVNM Mesh connectivity. To ensure on-premises traffic avoids inspection, set "Propagate Gateway Routes" to true in the UDRs applied to spoke VNets. This allows traffic to follow the ExpressRoute path directly without being inspected in Azure. Scenario2: vWAN Inspection Options Now we will explore inspection options using a vWAN topology. Across all scenarios, the base architecture assumes two Virtual Hubs (VHubs), each connected to its respective local spoke VNets. vWAN provides default connectivity between the two VHubs, and each VHub is also connected to both local and remote ExpressRoute circuits for redundancy. It's important to note that this discussion focuses on inspection in vWAN using Routing Intent. As a result, bypassing inspection for traffic to on-premises is not supported in this model. Option1: Full Inspection As noted earlier, inspecting all traffic, both east-west and north-south, is a common practice to fulfill compliance and security needs. In this design, enabling Routing Intent provides the capability to inspect both, private and internet-bound traffic. Unlike the Hub-and-Spoke topology, this approach does not require any UDR configuration. Connectivity Inspection Table Connectivity Scenario Inspected On-premises ↔ Azure ✅ Spoke ↔ Spoke ✅ Spoke ↔ Internet ✅ Option2: Using Different Firewall Flavors for Traffic Inspection Using different firewall flavors inside VHub for traffic inspection Some customers require specific firewalls for different traffic flows, for example, using Azure Firewall for East-West traffic while relying on a third-party firewall for North-South inspection. In vWAN, it’s possible to deploy both Azure Firewall and a third-party network virtual appliance (NVA) within the same VHub. However, as of this writing, deploying two different third-party NVAs in the same VHub is not supported. This behavior may change in the future, so it’s recommended to monitor the known limitations section for updates. With this design, you can easily control which firewall handles East-West versus North-South traffic using Routing Intent, eliminating the need for UDRs. Using different firewall flavors inside VHub for traffic inspection Deploying third-party firewalls in spoke VNets when VHub limitations apply If the third-party firewall you want to use is not supported within the VHub, or if the managed firewall available in the VHub lacks certain required features compared to the version deployable in a regular VNet, you can deploy the third-party firewall in a spoke VNet instead, while using Azure Firewall in the VHub. In this design, the third-party firewall (deployed in a spoke VNet) handles internet-bound traffic, and Azure Firewall (in the VHub) inspects East-West traffic. This setup is achieved by peering the third-party firewall VNet to the VHub, as well as directly peering it with the spoke VNets. These spoke VNets are also connected to the VHub, as illustrated in the diagram below. UDRs are required in the spoke VNets to forward internet-bound traffic to the third-party firewall VNet. East-West traffic routing, however, is handled using the Routing Intent feature, directing traffic through Azure Firewall without the need for UDRs. Deploying third-party firewalls in spoke VNets when VHub limitations apply Note: Although it is not required to connect the third-party firewall VNet to the VHub for traffic flow, doing so is recommended for ease of management and on-premises reachability. Connectivity Inspection Table Connectivity Scenario Inspected On-premises ↔ Azure ✅ Inspected using Azure Firewall Spoke ↔ Spoke ✅ Inspected using Azure Firewall Spoke ↔ Internet ✅ Inspected using Third Party Firewall Option3: Selective Inspection Between Azure VNets Similar to the Hub-and-Spoke topology, there are scenarios where full traffic inspection is not ideal. This may be due to Azure VNets being segmented into trusted and untrusted zones, where inspection is unnecessary between trusted VNets. Other reasons include large data replication between specific VNets or latency-sensitive applications that require minimizing inspection delays and associated costs. In this design, trusted and untrusted VNets can reside within the same VHub or across different VHubs. Routing Intent remains enabled to inspect traffic between trusted and untrusted VNets, as well as internet-bound traffic. To bypass inspection between trusted VNets, you can connect them directly using VNet Peering or AVNM Mesh connectivity. Unlike the Hub-and-Spoke model, this design does not require UDR configuration. Because trusted VNets are directly connected, system routes from VNet peering take precedence over routes learned through the VHub. Traffic destined for untrusted zones will continue to follow the Routing Intent and be inspected accordingly. Connectivity Inspection Table Connectivity Scenario Inspected On-premises ↔ Azure ✅ Spoke ↔ Internet ✅ Spoke ↔ Spoke (Same Zones) ❌ Spoke ↔ Spoke (Across Zones) ✅ Option4: Internet Inspection Only While not generally recommended, some customers choose to inspect only internet-bound traffic and bypass inspection of private traffic. In this design, you only enable the Internet Inspection option within Routing Intent, so private traffic bypasses the firewall entirely. The VHub manages both intra-and inter-VHub routing directly. Internet Inspection Only Connectivity Inspection Table Connectivity Scenario Inspected On-premises ↔ Azure ❌ Spoke ↔ Internet ✅ Spoke ↔ Spoke ❌
