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Difficulty: MediumCreate and Configure Virtual Networks and Subnets

You are planning the deployment of a new workload in Azure. You have an Azure virtual network named `vnet-manufacturing` with an address space of 10.150.0.0/1610.150.0.0/16. You create a subnet named `snet-assembly` with an address prefix of 10.150.10.0/2910.150.10.0/29. You need to deploy 44 virtual machines in `snet-assembly` that each require a dedicated private IP address.

Statement: The 10.150.10.0/2910.150.10.0/29 subnet address space is sufficient to host the 44 virtual machines.

Answer: Answer

Answer

The statement is false. An Azure subnet with a /29/29 prefix provides 88 total IP addresses. Since Azure reserves five IP addresses in every subnet, only 33 IP addresses are usable, which is insufficient for 44 virtual machines.
The statement is false. In Azure, every subnet reserves five IP addresses: the first four addresses and the last address. For a /29/29 subnet, the total number of IP addresses is 88. Subtracting the 55 reserved addresses leaves only 33 usable IP addresses. This is not enough to support the 44 required virtual machines.

Step-by-Step Solution

1
Calculate the total number of IP addresses in a /29/29 subnet.
A /29/29 subnet contains 232−29=23=82^{32-29} = 2^3 = 8 total IP addresses.
Determining the total IP address space of the subnet.
2
Subtract the number of Azure reserved IP addresses.
There are 8−5=38 - 5 = 3 usable IP addresses.
Azure reserves five IP addresses in every subnet: the first four IPs and the last IP.
3
Compare the number of usable IP addresses to the requirements.
33 usable IP addresses are less than the 44 required IP addresses.
To verify if the subnet can host the specified number of virtual machines.

Key Concept

Azure Virtual Network subnet size calculations and reserved IP addresses
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Topics

Create and Configure Virtual Networks and Subnets