Looks like elastic search is not discoverable without setting the box's ip address in this property : network.host .
Why cant it just bind to the box's ip address(like it happens in application servers like rest apps). Why is there even a provision to bind to a particular ip address?
The key property that matters is network.publish_host. You configure this indirectly via network.host. The publish host is the address that nodes advertise to other nodes as the address to be reached on when they join the cluster. So, it needs to be something that is reachable from the other nodes. E.g. 127.0.0.1 would not work for this; likewise a loadbalanced address won't work either.
Also see documentation for these properties
Many servers have multiple network interfaces and a common problem before this change was Elasticsearch picking the wrong one for the publish host and then failing to cluster because the nodes ended up advertising the wrong address to each other. Since Elasticsearch cannot know the right interface, you have to tell it.