Dear all,
We have had the same problem. Then we decided to “destroy” the VMs and install the cluster again. Then, we put a lot of attention on all the pre-requisites, in particular to the
4.1. Set Up Password-less SSH step of the official installation guide.
After you do all the required checks, you should then be able to ssh from each VM to the other (if you do not do these checks, you would not be able to do it).
The cluster installation, this time, ended with no issues.
Hope it helps!
Massimiliano