AZ-700 Question 3
Single answerYou are designing an Azure Virtual Network (VNet) for a multi-tier application. Your on-premises data center currently uses 10.0.0.0/16, but there are plans to expand this to the broader 10.0.0.0/8 range in the future. You need to ensure that your Azure VNet has sufficient IP space to segment front-end, middle-tier, and database subnets while avoiding any overlapping IP addresses with on-premises networks, both now and after the expansion. Which address space should you choose for your Azure VNet?
- A
A. 10.0.10.0/16
- B
B. 10.10.0.0/16
- C
C. 172.16.0.0/12
- D
D. 192.168.0.0/16
Show answer and explanation
Correct answer: C
Explanation
When planning Azure VNet address spaces, one of the key considerations is avoiding overlap with existing or future on-premises IP ranges. Although both 172.16.0.0/12 and 192.168.0.0/16 could be used, 172.16.0.0/12 provides a larger non-overlapping range for segmenting multiple tiers (front-end, middle-tier, and database). Microsoft documentation recommends reserving non-overlapping IP spaces especially when future expansion is a concern. Reference: 'Designing IP addressing for Azure VNets' in Microsoft Learn.
- A. Incorrect.
A. 10.0.10.0/16 uses the 10.0.x.x space, which is already in use and planned to expand to /8 in the future. This would create overlapping addresses over time, making it an incorrect choice.
- B. Incorrect.
B. 10.10.0.0/16 is still part of the 10.x.x.x range. If on-premises expands to 10.0.0.0/8, you would eventually introduce address conflicts, making this option incorrect.
- C. Correct.
C. 172.16.0.0/12 falls outside the 10.x.x.x range and provides ample space for multiple subnets. It avoids the overlap problem if on-premises expands its 10.0.0.0/8 network, making this the best choice.
- D. Incorrect.
D. 192.168.0.0/16 is also outside the 10.x.x.x range and could work in many scenarios. However, the 172.16.0.0/12 space offers more subnetting flexibility if you need additional segments in the future. While 192.168.0.0/16 wouldn�t overlap, it might be restrictive compared to a /12 range. Option C is still the most optimal.