I am sorry, I did not make myself clear. Let me try again:
1. I am creating volume SnapMirror, not using SnapManager.
2. I am doing so from Source cluster GUI. When I clieck on Mirror, it bring me to next page, requires me to enter the new volume name on DEST cluster, and all other SM configurations. Before that, I need to enter authentication information to connect the DR cluster. I am getting "Cluster unreachable", after I enter them.