Exam AZ-305 topic 4 question 86 discussion

Minimizes latency by supporting connection in three regions The requirement to “minimize latency by supporting connection in three regions” suggests that connections should be optimized across three regions. However, the solution also needs to connect to ExpressRoute circuits in four specific Azure regions: East US, Southeast Asia, North Europe, and South Africa. To meet all these requirements, a hub should be deployed in each of these four regions. This ensures that each region has a local connection point, reducing latency. Even though connections are optimized across three regions, the fourth hub is necessary to provide a local connection point in the fourth region. So, while three hubs might seem sufficient based on one requirement, considering all requirements makes it clear that four hubs are needed. This is a common scenario in network planning where various factors and requirements must be balanced.

But why is it 3 virtual hubs, if we have 4 localisations?

CORRECT We need at least 3 Virtual WAN hubs strategically placed to cover the requirements: East US (to support New York City) Southeast Asia (to support Sydney) North Europe (to support Paris) South Africa may be covered by connecting to a hub in North Europe if minimal latency is acceptable. Deploying a fourth hub in South Africa would optimize performance for Johannesburg. However, for cost minimization and if only three hubs are required, it could be excluded.

I got this question in November 2024, but it changed slightly. It no longer asks about the virtual WAN SKU - hub number only.

as per microsoft : You can establish a virtual WAN by creating a single virtual WAN hub in the region that has the largest number of spokes (branches, VNets, users), and then connecting the spokes that are in other regions to the hub. This is a good option when an enterprise footprint is mostly in one region with a few remote spokes `` accoprdingly, no technical obligation to connect the 4th region to a separate virtual hub, so based on the reqs. 3 Hubs are enough. https://learn.microsoft.com/en-us/azure/virtual-wan/virtual-wan-global-transit-network-architecture

Personally, I would have chosen 4 virtual hubs to not leave a region out of support, but the request is clear and they want to minimise costs...No other choice than a poor design like that. 3 Virtual Hubs in three regions of our choice.

My take on this is 4 hubs: East US, Southeast Asia, North Europe, and South Africa and SKU: Standard because Basic ONLY supports S2S VPN In terms of this requirements "Minimizes latency by supporting connection in three regions" it is feature of the STD SKU called Inter-hub and VNet-to-VNet transiting through the virtual hub follow next as no space

4 hubs: East US, Southeast Asia, North Europe, and South Africa and SKU: Standard

should have 4 hub as ExpressRoute should not connect cross region.

SKU: Standard, because: Basic: Site-to-site VPN only Standard: ExpressRoute, User VPN (P2S), VPN (site-to-site), Inter-hub and VNet-to-VNet transiting through the virtual hub, Azure Firewall, NVA in a virtual WAN Source: https://learn.microsoft.com/en-us/azure/virtual-wan/virtual-wan-about

4 hubs, standard sku.

deploy at least three Azure Virtual WAN hubs in order to minimize latency by supporting connections in three regions. As for the SKU, the Basic SKU does not support ExpressRoute or site-to-site VPN connections, so you would need to use the Standard SKU to meet all the requirements.

A Basic hub is limited to site-to-site VPN functionality only. When you upgrade from Basic to Standard, all the hubs within the virtual WAN are upgraded to Standard hubs. Standard hubs support ExpressRoute, point-to-site (User VPN), a full mesh hub, and VNet-to-VNet transit through the Azure hubs.

Site-to-site VPN only => Basic virtual WAN only. Standard => ExpressRoute available.