Forward traffic from NLB to ALB in https


Hello, I have the following setup -> API Gateway -> (through VPC Link) NLB (internal facing) -> ALB (internal facing)-> ECS.

The NLB has a listener for the 443. It forwards to the ALB target groups for TCP 443.

When i tired https://"NLB domain":443 in api gateway, i got "Execution failed due to configuration error: PKIX path building failed: unable to find valid certification path to requested target" error. What am i missing here? The listener for ALB target group doesn't allow certificate.

Any help would be appreciated. Thank you!

asked 22 days ago38 views
1 Answer


If you want to perform HTTPS communication toward NLB-ALB after SSL termination at API Gateway, you need to use ACM to configure SSL certificate and listener on NLB or ALB.

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answered 19 days ago
  • Hello iwasa, Do you know how to configure on NLB? I don't see such option when i use the ALB target group. Thank you!

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