Designing and Implementing Azure for AWS Professionals — Question 27
A company hosts a highly available application using Azure Load Balancer.
A virtual machine (VM) on the backend pool stops responding to health probes. The health probes are configured to use HTTP.
You are troubleshooting the incoming traffic issue. You run a Netsh trace on port 80. No incoming packets are detected on the VM. Outgoing packets are detected.
What is the cause of the issue?
Answer options
- A. A network security group is preventing incoming traffic to the port.
- B. A proxy is configured.
- C. Session persistence is configured.
- D. An application on the VM is blocking the port.
Correct answer: A
Explanation
The correct answer is A, as a network security group (NSG) can restrict incoming traffic to specific ports, including port 80. Since no incoming packets are detected on the VM, it indicates that the NSG is likely blocking the traffic. The other options do not explain the absence of incoming packets effectively; a proxy would not prevent incoming packets from reaching the VM, session persistence relates to user sessions rather than traffic flow, and an application blocking the port would still show incoming packets being received.