Global L4 Load Balancer → AKS Service (LoadBalancer) traffic not receiving.

Hey @WiJungle Admin,

It sounds like you're experiencing some connectivity issues when trying to route traffic through a Global Load Balancer to your Azure AKS Services deployed across two regions. Here’s what you can look into to troubleshoot this situation:

Troubleshooting Steps:

1. Check Health Probes: Ensure that the health probes for the back-end resources (your AKS pods) are configured correctly. If the probes show as unhealthy, the Global Load Balancer won't route traffic to those pods. Check the health probe rules and confirm that your AKS pods can respond.
2. Network Security Groups (NSGs): Make sure that the NSGs associated with your AKS cluster allow traffic from the Global Load Balancer. You might need to explicitly permit inbound traffic on the designated ports.
3. Load Balancer Rules: Verify that you have the right load balancing rules set up on the Global Load Balancer to direct traffic to the correct ports on your AKS service.
4. Traffic Mapping: When traffic flows from the Global Load Balancer to your AKS service, it must be mapped correctly. If the flow appears to go back to the same node that originated the request, it can lead to issues. Consider setting externalTrafficPolicy to Local in your AKS service definition to maintain the client’s IP.
5. Cross-Region Connectivity: Given that you're routing traffic across regions, ensure that the underlying VNet resources are correctly peered and that routes are established for cross-region traffic.
6. Debugging Commands: You can run the following commands to check the status:
   • kubectl get svc to check the status of your services.
   • kubectl describe svc <service-name> to get detailed information about the service configurations.

Additional Resources

• For more information on resolving load balancer issues in AKS, you can check the following documents:
  • How to use an internal load balancer with Azure Kubernetes Service
  • Azure load balancer SKU comparison
  • Limitations of Standard Load Balancer
  • Debug Services

Follow-Up Questions

1. What do the health probes show for the AKS service? Are they passing or failing?
2. Have you checked if the NSGs are configured properly for the AKS service and the Global Load Balancer?
3. Can you confirm if the load balancing rules are correctly set up for the Global Load Balancer?
4. Are there any specific errors you are seeing in the logs when trying to access the service?

Hope this helps you get to the bottom of the issue! If you need further assistance, feel free to ask.