I configured an AWS Load Balancer. It is working find on HTTP, but when I try over HTTPS I get a 504 Gateway Timeout Error. I tried all the suggestions on AWS's help page (increase idle timeout), but no luck. Any ideas why it wouldn't work over HTTPS, but still work over HTTP?
Both the Instance and Load Balancer security groups have HTTP and HTTPS enabled
The load balancer has HTTP and HTTPS listeners (note the LB does not terminate the SSL cert, it has 443 on front and back end port)
If I change it to be 443/80 (front/back) it works.
I do want it to be 443/443. But when I set it up this way I get the 504 error.
Best Answer
Make sure that you've selected HTTPS as Instance protocol. I've had set 443 both as LB and instance ports but HTTP selected as Instance Protocol and exactly the same behaviour.