Error Message

BEREMOTE [ndmp\ndmpclient] - getAuthenticationError: ERROR returning: 0x17, 23

To configure Dell Unity NDMP backup the "NAS Server" name or IP address must be added to Backup Exec..

Logon to Dell Unity Web interface and navigate to Storage | Files | NAS Servers. Figure 1

Figure 1

Figure 2

Enable NDMP on the "NAS Server"

Figure 3 

Unity OS requires to logon to CLI as an account called "service". This is the only account that has rights to issue CLI commands to confirm or configure ndmp configuration.

SSH user is "service" and then admin password.
https://www.dell.com/support/kbdoc/en-uk/000189645/avamar-how-to-create-modify-verify-unity-ndmp-user-settings

https://www.dell.com/support/kbdoc/en-us/000022637/unity-how-to-enable-and-configure-ndmp-user-correctable

Examples:

uemcli -d 10.x.x.x -u Local/admin -p P@ssw0rd /net/nas/ndmp show
uemcli /net/nas/server show
uemcli -d 10.x.x.x -u Local/admin -p P@ssw0rd /net/nas/ndmp -server nas_1 show
 

Backup Exec Selections after adding "Nas Server" Name or IP to Backup Exec.

Figure 4

TROUBLESHOOTING:
Telnet port 10000 to Management port fails (Port 10000 NDMP port)
Telnet port 10000 on "NAS Server" IP or Name connects (Port 10000 NDMP port)
SSH into Unity requires "service" account logon to issue CLI commands to confirm ndmp configuration.

Note: Dell support indicated the "ndmp" user is case sensitive and was capital letters "NDMP". Change the ndmp user to lowercase "ndmp".