SSH Connect to NAS

Well, I can SSH to the NAS, using a normal user "jim", but the connection is closed right away - I presume the Welcome message means the password was accepted. Then I tried to SSH as user "root" but I don't know the password. I tried nothing (CR) and "password" and the admin user's password - none work.

jim@WS-2 ~/Desktop $ ssh jim@192.168.0.215
jim@192.168.0.215's password: 

Welcome to ReadyNASOS 6.1.9

Connection to 192.168.0.215 closed.

jim@WS-2 ~/Desktop $ ssh root@192.168.0.215
root@192.168.0.215's password: 
Permission denied, please try again.
root@192.168.0.215's password: 
Permission denied, please try again.
root@192.168.0.215's password: 
Connection closed by 192.168.0.215
jim@WS-2 ~/Desktop $ 

How do I find out what NetGear set as the root password? I looked in the software documents for OS6 and it is not there. I don't think I want to use it, but I should know it and stash that information away somewhere in case I do need it some day.

So SSH to the NAS for one of the normal users on the NAS connects but then something on the NAS is closing the connection right away. User jim is valid on all my Linux computers and the NAS all with the same UID value and password. The user I used in the rsync command is not a user on any computers, nor the NAS. It was created only for rsync. Therefore that user does not have an entry in any /etc/passwd or is a member of any group on any of my computers, all my normal users on the computers have the shell set to /bin/bash. SSH to the NAS using that rsync user fails, the same as root in the code block above - it will not accept the valid password.

Thanks