I want to make a container hosted on one EC2 host communicate with another container hosted on another EC2 host.
Currently, if I send an HTTP request from host A to host B using host B's private DNS and the exposed container port, I receive a response correctly. However, if I try the same thing within the container on host B, I get a "Host is unreachable" error. To me, this would indicate it is not a host networking issue, which is configured in AWS, so I won't enter into detail on it.
What puzzles me is that I have done the exact same thing in our pre-production environment and it works perfectly.
What could be the issue and where do you think I should look to troubleshoot this?