The answer to my problem was an incompatibility between ViPR V2.3 and the not-yet-released DDMC version I was using.  Once I used a supported DDMC version, all was well.
Hi  I'm using ViPR Controller vipr-2.3.0.1.846, and am trying to add a Data Domain Management Center (DDMC) as a storage provider. I select 'Storage Providers' -> 'Add', fill out the form, select 'Data Domain Management Center' as the 'Type', and click OK. I get the error message, "Failed to establish connection to the storage provider". I am able to connect via HTTPS to the DDMC, and log in using the same credentials that I provided to ViPR.  How can I diagnose this problem?  Thanks tl
Problem adding a DDMC storage provider