Diagram
A decision tree for troubleshooting Azure Load Balancer health probe failures, starting from backend health status and branching through protocol, port, NSG, and resource utilization checks to isolate the root cause.
Non-Responsive Virtual Machines
When virtual machines in the backend pool do not respond to traffic on the configured data port, check two primary areas. First, ensure the VM is listening on the target port by running netstat -an in the command prompt; if the port is not listed as LISTENING, configure the proper listener port. Second, network security groups (NSGs) might block the port or source IP. Verify the security group settings to ensure the IP address of the clients is allowed, and confirm that the load balancer infrastructure IP (168.63.129.16) is not blocked.
Domain 3 of 3
33 practice questions
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