I have 2 Instance groups and HTTP load balancers for each one. Instance groups contain VMs that work on Windows Server 2012 with IIS inside.
When I send POST request from VM from one instance group to another using IP of its load balancer, I get 502 error instead of response.
Also sometimes I get this error when send GET requests.
When I send request directly to VM anything works correct.
What is the reason and how to fix error responses from load balancers?