I have created a MERN Stack project,Project is deployed on AWS in 2 parts(front-end and back-end), Front-end(React.js) is deployed in public subnet and Back-end(Node.js, Express, MongoDB) is deployed into private subnet, both subnets is in same VPC, public subnet is connect to IG(Internet Gateway) and private subnet is connected with NAT Gateway.

Front-end listening port: 3000
Backend-end listening port: 3300

Front-end and Back-end Secuirty Group:
Inbound and Outbound rule:-
All Traffic IPv4 0.0.0.0/0

Network ACL:
All Traffic 0.0.0.0/0 allowed

I’m able to ping from Private Subnet to public internet, but not able to ping from front-end public subnet to private subnet.

Don’t know what is happening.

I did troubleshoot many ways but not able to get the API response into front-end. I’m making API call to the Private Subnet IP of back-end EC2 instance.