Mastering Virtual Hub Routing in Azure: A Comprehensive Guide

In the dynamic world of cloud infrastructure, the ability to manage and configure routing within your virtual hubs is crucial for maintaining seamless connectivity and efficient data flow. This comprehensive guide will walk you through the process of configuring virtual hub routing using the Azure portal, helping you unlock the full potential of your Azure Virtual WAN network.

Understanding Virtual Hub Routing

A virtual hub in Azure Virtual WAN can contain multiple gateways, such as site-to-site VPN, ExpressRoute, point-to-site, and Azure Firewall. The routing capabilities within the virtual hub are provided by a router that manages all routing, including transit routing, between these gateways using the Border Gateway Protocol (BGP). This virtual hub router also enables transit connectivity between virtual networks connected to the hub, with the ability to support up to 50 Gbps of aggregate throughput.

These powerful routing capabilities are particularly beneficial for customers using the Standard tier of Azure Virtual WAN, as they provide advanced control and flexibility over your network infrastructure.

Creating a Route Table

Let’s start by exploring the process of creating a route table and a route within your virtual hub:

  1. Navigate to the Azure portal and locate your virtual hub.
  2. In the left pane, select Route Tables to open the Route Tables page, where you can observe the existing route tables propagated to this virtual hub.
  3. Click + Create route table to open the Create Route Table page.
  4. On the Basics tab, provide a name for your route table instance and the route. Select the appropriate Destination type from the dropdown, and specify the Destination prefix. This could be an aggregation of prefixes from your virtual networks, or a Branch route that applies to all connected VPN sites, ExpressRoute circuits, and user VPN connections.
  5. Choose the Next hop from the available options, which can include virtual network connections or Azure Firewall.
  6. If you select a virtual network connection as the next hop, you’ll be able to configure static routes as an optional setting.
  7. Navigate to the Labels page to configure label names, which provide a mechanism to logically group your route tables.
  8. On the Associations page, associate your connections (Branches, Virtual Networks, and the Current settings) to the route table.
  9. Finally, on the Propagations page, select the settings to propagate routes from your connections to the route table.
  10. Review the details and click Create to finalize the creation of your route table.

Editing Route Tables and Routes

Maintaining your routing configurations over time is essential, and Azure Virtual WAN makes it easy to edit both route tables and individual routes:

  1. Navigate to the virtual hub, select Route Tables in the left pane, and click the name of the route table you want to edit.
  2. On the Edit route table page, make the necessary changes to the values you want to update.
  3. When you’re done, click Create on the Propagations page to update the route table with the new route information.

To edit a specific route within a route table:

  1. Follow the same steps to navigate to the Route Tables page and select the route table containing the route you want to edit.
  2. On the Edit route table page, locate the route from the list and make the applicable changes. Click Review + create to save the updates.
  3. On the Propagations page, make any additional changes (if necessary) and click Create to update the route table.

Deleting Routes and Route Tables

Occasionally, you may need to remove routes or entire route tables from your virtual hub. Here’s how you can do it:

To delete a route:

  1. Navigate to the Route Tables page, click the name of the route table containing the route you want to delete.
  2. On the Edit route table page, locate the route you want to remove and click the ellipsis (three dots) at the end of the line.
  3. Select Remove from the dropdown menu, then click Review + Create and Create to finalize the deletion.

To delete a route table:

  1. Go to the Route Tables page, select the checkbox for the route table you want to delete (do not click the name).
  2. On the right side of the line, click the ellipsis and select Delete from the dropdown.
  3. Confirm the deletion on the Delete page, and the route table will be removed.

Viewing Effective Routes

Monitoring the effective routes in your virtual hub is crucial for understanding and validating your routing configurations. Follow these steps to access the Effective Routes page:

  1. In the Azure portal, navigate to your Virtual HUB and select the Effective Routes page.
  2. From the dropdowns, select the route table you want to view. The Effective Routes section will display the routes learned by the selected route table, including those propagated from your connections.
  3. To download this information as a CSV file, click the Download button at the top of the page.

Configuring Routing for Virtual Network Connections

To complete the virtual hub routing configuration, you’ll need to connect your virtual networks to the hub and configure the routing settings. The Connect Virtual Network to a Virtual WAN Hub guide provides step-by-step instructions for this process.

Conclusion

Mastering virtual hub routing in Azure Virtual WAN is a crucial skill for optimizing your cloud network infrastructure. By following the comprehensive steps outlined in this guide, you’ll be able to create, edit, and manage your route tables and routes with confidence, ensuring efficient and reliable data flow across your virtual networks. Remember to refer to the About Virtual Hub Routing and Virtual WAN FAQ resources for additional information and best practices.

Source: How to configure virtual hub routing - Azure portal