AZ-700 Question 166
Single answerYour company hosts a three-tier web application in a single Azure region. The application� front-end must be accessible from the internet, but the database tier must only be accessible through the front-end. Traffic volumes are high, and you need sufficient ephemeral ports to handle bursts of concurrent connections. Which Azure Load Balancer design best meets these requirements?
- A
Use a Basic Public Load Balancer for the front-end and rely on default inbound NAT for the database tier
- B
Use a Standard Public Load Balancer with inbound NAT rules for front-end access and an Internal Standard Load Balancer for the database tier
- C
Create multiple Basic Load Balancers, each with a separate public IP, to handle traffic for the front-end, application, and database tiers
- D
Use a Standard Public Load Balancer for the front-end and connect the database tier directly to the same public IP
Show answer and explanation
Correct answer: B
Explanation
Using a Standard Public Load Balancer for public-facing traffic and an Internal Standard Load Balancer for private tiers is a common best practice for secure, high-scale deployments in Azure. It supports more ephemeral ports, configurable inbound NAT rules, and better health probing capabilities. For more information, see: https://learn.microsoft.com/azure/load-balancer/load-balancer-overview.
- A. Incorrect.
Option 1 is incorrect because a Basic Load Balancer provides limited functionality, fewer ephemeral ports, and does not support advanced security and scaling features required for large-scale deployments. You also lack a dedicated internal balancing solution for the database tier.
- B. Correct.
Option 2 is correct. A Standard Load Balancer supports more ephemeral ports, provides inbound NAT rules for regulated front-end access, and can be paired with an Internal Standard Load Balancer to limit database traffic to your private network. This design meets the requirement to securely expose only the front-end, supports high traffic volumes, and maintains separation of tiers.
- C. Incorrect.
Option 3 is incorrect because deploying multiple Basic Load Balancers with separate public IPs complicates the design and does not adequately address the need for scale and secure traffic segmentation. It also limits advanced feature sets such as configurable outbound rules and more robust health probes found in the Standard tier.
- D. Incorrect.
Option 4 is incorrect because it places the database tier under the same public IP, which violates the requirement to access the database tier only through the front-end. Additionally, a single front-end Standard Load Balancer is typically sufficient for high-volume traffic, especially when used with an internal load balancer for private tiers.