An administrator is planning the deployment of a new Azure virtual network named `VNet-Pro… — Microsoft Azure Administrator (AZ-104)

An administrator is planning the deployment of a new Azure virtual network named `VNet-Prod` in an Azure subscription. The address space for `VNet-Prod` is configured as $10.200.0.0/22$ . The virtual network must support the following requirements:
- A subnet named `Subnet-App` that provides a minimum of 12 usable IP addresses for application servers.
- A subnet for secure administrative access to virtual machines using Azure Bastion.
- A subnet for a virtual network gateway to support a hybrid VPN connection.

The administrator wants to minimize address space allocation for each subnet.

Which three of the following subnet allocations should the administrator configure?

A subnet named `Subnet-App` with an address range of $10.200.0.0/27$ Answer
A subnet named `AzureBastionSubnet` with an address range of $10.200.0.32/26$ Answer
A subnet named `GatewaySubnet` with an address range of $10.200.0.96/29$ Answer
D
A subnet named `Subnet-App` with an address range of $10.200.0.0/28$
E
A subnet named `AzureBastionSubnet` with an address range of $10.200.0.32/27$
F
A subnet named `GatewaySubnet` with an address range of $10.200.0.96/30$

Answer

The correct subnet allocations are: the application subnet configured with a prefix of /27, the Azure Bastion subnet configured with a prefix of /26, and the GatewaySubnet configured with a prefix of /29.

The subnet named `Subnet-App` configured as

10.200.0.0/27

is correct because a /28 subnet provides only 11 usable IP addresses after accounting for the 5 IP addresses reserved by Azure (

16 - 5 = 11

), which is insufficient for the 12 hosts required. The subnet named `AzureBastionSubnet` configured as

10.200.0.32/26

is correct because Azure Bastion has a strict requirement of a dedicated subnet named exactly `AzureBastionSubnet` with a minimum subnet prefix length of /26. The subnet named `GatewaySubnet` configured as

10.200.0.96/29

is correct because a virtual network gateway requires a dedicated subnet named exactly `GatewaySubnet` with a minimum prefix length of /29.

Step-by-Step Solution

Determine the minimum size for the application subnet by accounting for Azure's reserved IP addresses.

The application subnet requires 12 usable host IP addresses. A /28 subnet provides 16 total IP addresses, but subtracting Azure's 5 reserved IP addresses leaves only 11 usable IPs (

16 - 5 = 11

). A /27 subnet provides 32 total IP addresses, leaving 27 usable host IPs (

32 - 5 = 27

), which satisfies the requirement.

Azure reserves the first four and the last IP address in each subnet for system usage.

Determine the minimum size and configuration requirements for the Azure Bastion subnet.

Azure Bastion requires a dedicated subnet named exactly `AzureBastionSubnet` with a minimum prefix length of /26.

A subnet smaller than /26 (such as /27) is not supported for Azure Bastion deployments.

Determine the minimum size and configuration requirements for the VPN Gateway subnet.

The virtual network gateway requires a dedicated subnet named exactly `GatewaySubnet` with a minimum prefix length of /29.

A subnet smaller than /29 (such as /30) is not supported for GatewaySubnet configurations.

Key Concept

Subnet sizing and service-specific naming and prefix constraints in Azure Virtual Networks, including Azure's 5 reserved IP addresses, `AzureBastionSubnet` sizing requirements, and `GatewaySubnet` sizing requirements.

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

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