Over the past few years I have been promoting customers to adopt the Microsoft/Azure’s Hub-Spoke (Hub and Spoke) network topology and its architecture. Not too long ago (Ignite 2019), Azure has made some significant improvements with their architecture and best practices by introducing “Virtual WAN“. I like to call this new service and evaluation as the new Hub-Spoke architecture version 2.0.
What is Azure Virtual WAN?
Azure Virtual WAN, or vWAN is a networking solution/service that allows you to integrate key functionalities such as networking, routing and security within a single pane. Azure vWAN is really a software-defined (SD) solution of WAN based technologies, and similar to service endpoints, and private links, Azure vWAN leverages the Microsoft network backbone to build a highly-available and high-speed global transit network. These functionalities include branch connectivity such as Site to Site VPNs, Point to Site VPN, ExpressRoute and intra-cloud/transitive networks, Azure Firewall and encrypted private connectivity.
Azure vWAN SKU Type
Microsoft has made it simple with the options you get with Azure vWAN, either basic or standard. Once you deploy Azure vWAN, you can get started with one of the use cases (as mentioned above) and add functionalities as your network evolves.
With Basic, you can only leverage vWAN for a Site to Site VPN connection. However once you go to the Standard SKU, you can now leverage all of the functionalities mentioned above, ie. Site to Site, Point to Site, ExpressRoute and Inter-Hub and VNet to VNet transiting via the vHUB.
Architecture (simplified) Overview
The image below depicts a high level but comprehensive with its capabilities on how Azure Virtual WAN can be integrated for various scenarios. With the “Any to Any” connectivity model, the Global transit network enables to connect your branch offices, remote users, datacenters, Azure VNets to one another. The image and model below, a spoke can be your Azure VNet, or a branch office, or a remote user, or perhaps the Internet. This architecture enables logical one-hop transit connectivity between the networking endpoints.
The Azure vWAN architecture is a hub and spoke architecture that incorporates scalability, resilience and performance built in for branches (VPN/SD-WAN devices), users (Azure VPN/OpenVPN/IKEv2), ExpressRoute circuits, and Azure virtual networks (VNets). There are some excellent benefits of using Azure Virtual WAN within your architecture as it simplifies the overall network topology and provides a handful of opportunities to integrate your on-premises datacenters, branch offices, remote users into a global transit network architecture. There are some limitations I can already see today, and that being not being able to leverage 3rd party network virtual appliances (NVA) such as Palo Alto, Checkpoint, etc., however I am sure that is already within the roadmap.