The following outlines how to check and set up passwordless ssh between nodes:
Note this should be done for the root user and dradmin user.
For each node verify it can SSH to itself and all the other nodes in the Data Repository cluster, without any password prompts.
ssh dradmin@localhost ls
ssh dradmin@node2 ls
ssh dradmin@node3 ls
Do this from all nodes to the other nodes as the dradmin.