After creating and configuring the NDMP VTL as shown on the following link:
https://support.quest.com/netvault-backup/kb/152611/how-to-configure-dr4100-as-a-ndmp-vtl-then-configure-with-netvault-backup
When trying to add the NDMP VTL to NVBU, after selecting the backup server and hitting next to discover the NDMP VTL, the following error shows up:
Warning No Tape Libraries found on client DC-NETVAULT
RDA Containers can be added without problem and network has already been configured to allow all traffic over port 10000.