AZ-700 Question 198
Select 2You have deployed a Standard Azure Load Balancer in front of three Linux virtual machines hosting an internal web application on port 80. To ensure traffic is only directed to healthy VMs, you need to configure a custom HTTP health probe that checks the /health endpoint. Which two actions must you take to properly configure and validate the Azure Load Balancer health probe for the application?
- A
A. Create a TCP probe on port 443 with a 5-second interval
- B
B. Configure an HTTP health probe on port 80 with the path set to /health
- C
C. Allow inbound traffic on port 80 in the VM Network Security Group (NSG) from the AzureLoadBalancer service tag
- D
D. Enable Accelerated Networking on all virtual machines in the backend pool
Show answer and explanation
Correct answers: B, C
Explanation
When configuring an HTTP health probe for an Azure Load Balancer, you must ensure that the probe uses the correct protocol (HTTP), port (80 in this scenario), and path (/health) that returns a 200 status code. Additionally, you need to permit the health probe traffic through the Network Security Group on the appropriate port (80), allowing inbound connections from the AzureLoadBalancer service tag. For more details, refer to the official Azure documentation on Load Balancer health probes: https://learn.microsoft.com/azure/load-balancer/load-balancer-custom-probe-overview.
- A. Incorrect.
A. Incorrect. A TCP probe on port 443 would not detect the HTTP status code (200 OK) from the /health endpoint on port 80. You must use an HTTP probe on the correct port for such checks.
- B. Correct.
B. Correct. To verify that each VM is responding properly to HTTP requests, you need to create an HTTP health probe on the same port (80) and set the path to /health. If the service returns 200 OK, the VM is considered healthy.
- C. Correct.
C. Correct. The Azure Load Balancer health probe traffic originates from the AzureLoadBalancer service tag. This traffic must be allowed inbound on port 80 so the probes can reach the VMs. Without this rule, the health probe fails.
- D. Incorrect.
D. Incorrect. While Accelerated Networking can improve performance, it is not required to configure or validate an HTTP health probe. The probe functionality works regardless of whether Accelerated Networking is enabled.