The branch-to-hub to hub-to-branch topology is a fundamental design pattern in Azure Virtual

WAN that enables global transit connectivity. This configuration allows branches connected to

different regional hubs to communicate with each other by routing traffic over the high-speed

Microsoft global backbone network. This significantly improves performance and reduces latency

for inter-branch data transfers compared to routing traffic over the public internet or hair-pinning

through a central on-premises datacenter. This architecture provides efficient, any-to-any

connectivity between geographically dispersed sites.

A: This topology is designed to enable communication between branches across different hubs,

which is the opposite of isolating them.

B: While Virtual WAN is scalable, this option is too general. The specific advantage of this

topology is the improvement and performance of branch-to-branch communication, not just

enabling it.

C: A branch typically connects to a single regional hub for optimal performance. The hub-to-hub

connection facilitates transit, not simultaneous multi-hub load balancing for a single branch.

1. Microsoft Azure Documentation, "Global transit network architecture with Azure Virtual WAN":

This document explicitly states that a key capability is "Any-to-any connectivity. For example, a

branch office can connect to another branch office... This connectivity is enabled by Virtual WAN

hub-to-hub communication."

URL:

https://learn.microsoft.com/en-us/azure/architecture/networking/hub-spoke-vwan-architecture

2. Microsoft Azure Documentation, "Azure Virtual WAN FAQ": In the connectivity section, it

confirms, "Virtual WAN provides branch-to-branch connectivity... This is accomplished by routing

through the Virtual WAN hubs. This allows branches to connect to other branches without having

to go through a data center."

URL: https://learn.microsoft.com/en-us/azure/virtual-wan/virtual-wan-faq#connectivity

3. Microsoft Azure Documentation, "About routing in a Virtual WAN hub": This page details how

routes are propagated between hubs, which is the mechanism that enables traffic to flow from a

branch in one region to a branch in another.

URL: https://learn.microsoft.com/en-us/azure/virtual-wan/about-virtual-hub-routing