Minimum ExpressRoute Circuits for Multi-Subscription Connectivity

Design, implement, and manage Azure ExpressRoute

Answer Correct answer: A — One ExpressRoute circuit is sufficient because it can connect up to 10 virtual networks across multiple subscriptions within the same geopolitical region (West US and West US 2).

Your company has an on-premises network and three Azure subscriptions named Subscription1, Subscription2, and Subscription3. The departments at the company use the Azure subscriptions as shown in the following table. [sampleXML/xmlfile-17_1.png] All the resources in the subscriptions are in either the West US Azure region or the West US 2 Azure region. You plan to connect all the subscriptions to the on-premises network by using ExpressRoute. What is the minimum number of ExpressRoute circuits required?

1 Correct Answer
2
3
4
5

Community Insight

The exam tests whether candidates understand that ExpressRoute circuits are shared resources per region rather than per-subscription, with the common trap being the assumption that separate subscriptions require separate physical connections.

This question examines the capacity of Azure ExpressRoute circuits to link multiple virtual networks across different subscriptions within the same geopolitical region. The correct answer is A, as a single Standard ExpressRoute circuit can connect up to ten virtual networks regardless of their subscription boundaries.

Many learners incorrectly select B (2) because they assume one circuit is needed for West US and another for West US 2, failing to recognize that both regions belong to the same geopolitical zone allowing for shared connectivity.

Community Discussion (22 comments)

geekmichael 👍 1 Selected: A

Microsoft Copilot: A single standard ExpressRoute circuit can be linked to virtual networks in multiple Azure subscriptions. All the resources are located in West US and West US 2, which are both within the North America geopolitical region. An ExpressRoute circuit provides connectivity to Azure services across all regions within the same geopolitical region. Therefore, one ExpressRoute circuit can connect the on-premises network to VNets in Subscription1, Subscription2, and Subscription3, provided they are in the same geopolitical region. ✅ Minimum number of ExpressRoute circuits required: 1. This is a common AZ-700 exam scenario where multiple subscriptions do not require multiple ExpressRoute circuits when the VNets are in the same geopolitical region.

kbakdev 👍 1 Selected: A

They are in the same region, and 1 ER circuit can support up to 10 VNets.

shaji111 👍 2 Selected: A

The question is not specifically asking which SKUs, the default is standard SKU, which can connect multiple region in the same geographical area , so answer A is most appropriate in this context.

IngeTahiti 👍 1 Selected: A

Correct answer.

thekhijir 👍 1 Selected: A

A One ER Required.

stormtraining 👍 6

people saying A-1 is correct have 0 knowledge of how Networking Infrastructure works. You need 2: Since all resources in the subscriptions are in either the West US or the West US 2 regions, and you plan to connect all the subscriptions to the on-premises network, you only need one circuit per region. Therefore, a total of two ExpressRoute circuits are required, one for West US and one for West US 2.

xRiot007 👍 2

Since all resources in the subscriptions are in either the West US or the West US 2 regions - if all resources exist in 1 region, Local SKU and 1 circuit is enough. The question does not even mention a SKU, it just asks about the number of circuits.

sapien45 👍 1 Selected: A

Not true for Local SKU though. . With a Local SKU ExpressRoute circuit you can connect to resources in Azure regions in the same metro as the peering site. In this case, your on-premises network can access UK South Azure resources over ExpressRoute. For more information, see What is ExpressRoute Local?. When you configure a Standard SKU ExpressRoute circuit, connectivity to Azure resources will expand to all Azure regions in a geopolitical area. https://learn.microsoft.com/en-us/azure/expressroute/expressroute-faqs

khanda 👍 4 Selected: A

You can link up to 10 virtual networks to a standard ExpressRoute circuit. All virtual networks must be in the same geopolitical region when using a standard ExpressRoute circuit. West US and West US 2 are in the same Azure geopolitical region, so you would need only one ER circuits. https://learn.microsoft.com/en-us/azure/expressroute/expressroute-howto-linkvnet-portal-resource-manager#connect-a-vnet-to-a-circuit---different-subscription https://learn.microsoft.com/en-us/azure/expressroute/expressroute-locations-providers

TheBlob 👍 1 Selected: A

Answer A is correct. As already mentioned by others you can connect 10 Virtual Networks to a single ExpressRoute Circuit (Standard SKU or higher required). What is important to understand is that those Virtual Networks (e.g., Virtual Network Gateways) must be in the same geographical region. Well, 'West US' and 'West US 2' are in the same geographical region.

Ben_88 👍 1 Selected: A

1 Express Route Circuit standard sku would be good enough. With 1 er circuit you can connect upto 10 vnets and standard sku allows you to connect within same geopolitical region without additional cost.

ESAJRR 👍 1 Selected: A

Answer: A - 1

mauchi 👍 1

if the express route would be with a standard SKU, then yes, I think A - 1 express route would be enough

Mo22 👍 3 Selected: B

B. 2 You need at least two ExpressRoute circuits to connect all three Azure subscriptions to the on-premises network. One circuit connects the West US Azure region and another circuit connects the West US 2 Azure region. All the resources in the subscriptions are in either the West US Azure region or the West US 2 Azure region, so you need to connect both regions.

AdityaGupta 👍 1 Selected: A

Ajdlfasudfo0 👍 3

it's in the same metro, so local is fine

Alessandro365 👍 1 Selected: A

Answer: A - 1

Jamesat 👍 4 Selected: A

ExpressRoute circuits can be shared between subscriptions. Correct answer is A

iwikneerg 👍 2

Looks like the correct answer is A You can have an ExpressRoute Circuit going into one region and gain access to other regions from there... Connectivity to all regions within a geopolitical region You can connect to Microsoft in one of our peering locations and access regions within the geopolitical region. For example, if you connect to Microsoft in Amsterdam through ExpressRoute. You'll have access to all Microsoft cloud services hosted in Northern and Western Europe. For an overview of the geopolitical regions, the associated Microsoft cloud regions, and corresponding ExpressRoute peering locations, see the ExpressRoute partners and peering locations article. https://docs.microsoft.com/en-us/azure/expressroute/expressroute-introduction#connectivity-to-all-regions-within-a-geopolitical-region

iwikneerg 👍 1

https://docs.microsoft.com/en-us/azure/expressroute/expressroute-locations#locations See North America geopolitical region

milan92stankovic 👍 4 Selected: A

Answer: A

7254kazu 👍 3

https://docs.microsoft.com/en-us/azure/expressroute/expressroute-howto-linkvnet-portal-resource-manager#connect-a-vnet-to-a-circuit---different-subscription

Comments & Corrections

No comments yet — spotted an error or have a note? Share it below.

Expert Analysis

Why the Answer Is Correct

A single ExpressRoute circuit can be shared across multiple virtual networks, even if those virtual networks reside in different Azure subscriptions. Since all resources are located in West US or West US 2, which are part of the same geopolitical region, one Standard ExpressRoute circuit is sufficient to provide connectivity to all virtual networks in both regions.

Why the Other Options Are Wrong

Options B through E suggest higher numbers of circuits, implying a need for dedicated connections per subscription or per specific region. This is incorrect because Azure allows sharing a circuit among up to 10 virtual networks within the same geopolitical region. There is no requirement to provision additional circuits unless you exceed the VNet limit or require multi-region redundancy outside the same geopolitical zone.

Community Comment Notes

Community consensus strongly supports option A. As user 'khanda' noted, "You can link up to 10 virtual networks to a standard ExpressRoute circuit... West US and West US 2 are in the same Azure geopolitical region." Another commenter, 'stormtraining', argued against the misconception that infrastructure requires distinct paths for every region, confirming that one circuit suffices when regions share a geopolitical identity.

Official Reference

https://learn.microsoft.com/en-us/azure/expressroute/expressroute-howto-linkvnet-portal-resource-manager#connect-a-vnet-to-a-circuit---different-subscription

Exam Strategy

When asked about the number of ExpressRoute circuits required, always check if the target VNets are in the same geopolitical region. If they are, remember that one Standard circuit can support up to 10 VNets across any number of subscriptions, minimizing the count to just one.

Frequently Asked Questions

Can an ExpressRoute circuit connect VNets from different subscriptions?

Yes, an ExpressRoute circuit can be shared by multiple virtual networks regardless of which Azure subscription they belong to, provided they are in the same geopolitical region.

Why do West US and West US 2 not require separate circuits?

Both regions fall under the same geopolitical region (Americas), allowing a single Standard ExpressRoute circuit to provide connectivity to virtual networks in either region.

More AZ-700 FAQ →

Related Analysis

Practice All AZ-700 Questions

Access 100 questions with complete answers and detailed explanations.

View Full AZ-700 Practice Test →

← Back to AZ-700 Study Guide