An administrator is configuring a virtual network named `vnet-prod-core` in an Azure subsc… — Microsoft Azure Administrator (AZ-104)

An administrator is configuring a virtual network named `vnet-prod-core` in an Azure subscription. The virtual network is configured with two address spaces:

* $10.240.0.0/16$
* $10.250.8.0/24$

The virtual network currently contains no subnets.

The administrator needs to deploy a new subnet named `subnet-compute` that will host virtual machines. The subnet must support at least $400$ virtual machines.

The administrator proposes to configure `subnet-compute` with the CIDR block $10.250.8.0/23$ .

Does the proposed configuration meet the requirements and successfully deploy?

Answer: Answer

Answer

The proposed configuration does not meet the requirements and will fail to deploy because the subnet range is not fully contained within any of the virtual network's defined address spaces.

The correct answer is False because the proposed CIDR block

10.250.8.0/23

requires the IP range

10.250.8.0

10.250.9.255

. This range is not fully contained within either of the virtual network's defined address spaces (

10.240.0.0/16

and

10.250.8.0/24

). Consequently, Azure Resource Manager will fail to deploy the subnet.

Step-by-Step Solution

Calculate the host capacity of the proposed subnet

10.250.8.0/23

/23

subnet contains

512

total IP addresses. Azure reserves

5

IP addresses in every subnet, leaving

512 - 5 = 507

usable IP addresses. This meets the requirement of supporting at least

400

virtual machines.

Determine if the proposed subnet size is mathematically sufficient to host the requested number of virtual machines after accounting for Azure's reserved addresses.

Evaluate the address space containment constraint for the proposed subnet.

The range of

10.250.8.0/23

spans from

10.250.8.0

10.250.9.255

. The virtual network's defined address spaces are

10.240.0.0/16

and

10.250.8.0/24

(covering

10.250.8.0

10.250.8.255

). The proposed subnet range exceeds the second address space boundary (specifically, the range

10.250.9.0

10.250.9.255

is not defined in the virtual network) and does not belong to the first address space.

Verify if the proposed subnet CIDR block falls entirely within one of the parent virtual network's defined address spaces.

Determine configuration validity and deployment outcome.

Since the proposed subnet range is not fully contained within a single defined address space of the virtual network, Azure will block the creation of the subnet, resulting in a deployment failure.

Apply Azure architectural rules to conclude whether the deployment succeeds or fails.

Key Concept

Every subnet created in an Azure virtual network must have an address range that is a subset of, and fully contained within, a single address space defined on the parent virtual network.

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

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