A company is troubleshooting an issue where SAP users cannot log in to the SAP GUI. The SAP application server is running on an EC2 instance behind an Application Load Balancer (ALB). The ALB is configured to use the HTTPS listener on port 443. Which configuration is most likely causing the issue?
SAP GUI uses DIAG (TCP 3200), not HTTP/HTTPS; an ALB is not suitable for non-HTTP traffic.
Why this answer
SAP GUI uses the DIAG protocol over TCP port 3200, not HTTPS. The ALB terminates HTTPS connections, but the backend SAP application server expects unencrypted DIAG traffic, so the protocol mismatch prevents successful login. Option A is incorrect because health checks affect target availability, not user authentication.
Option B is incorrect because port 3300 is not the standard DIAG port (3200 is), and security group rules are not the primary cause. Option D is incorrect because stickiness settings influence session persistence but do not block initial login when protocol mismatch exists.