When we try to start a cluster using the manager's floating ip (default) but necessary ports are not open (e.g: 15432), there is no appropriate error message.
It looks like the cluster started successfully, and only on the nodes list we can see that the node is offline and the DB status is "FAILED" (and of course cluster join will not work in that case).
The bug is reproducible. Also, if you try to join manager to the cluster you'll receive a wrong error message, saying that: "None of the cluster nodes are reachable: 10.239.2.105 (ports: 15432, 22000, 8300, 8301, 8500)", although only port 15432 is unreachable.
Added the following to the 4.1 Known Issues in the release notes
```If, when you start a cluster using the floating IP of a Manager(default), the required ports are not open, an error message is not displayed. It will appear that the cluster has started correctly.
Workaround: After you have started a cluster, view the Nodes list and verify that the node is online and does not have a FAILED DB status.
Added by starting a simple socket server on cluster start, and trying to connect to it.