Mapping drives between V-Nets and Different Domains

Question

Our setup is two domains. V-Nets 10.50.0.0/24 and 10.51.0.0/24 are part of the D2MSAZ.COM domain V-Net 10.54.0.0/24 is in the D2MSAZ2.COM domain Separate Domains/Forests. User accounts in D2MSAZ are “last name+First Initial” User accounts in D2MSAZ2 are “First Initial+Last Name” So dunns and sdunn for my accounts.

In the D2MSAZ domain there is only 1 DC, and it is on the 10.51.0.0 segment

From the RD Host server on 10.54.0.0 segment, I can map a drive to a VM in the 10.51.0.0 segment no problem. I can go to a run box and put in \VM1.d2msaz.com\c$ It will connect to the VM and ask for my username and password. Supply those, drive mapping completes.

If I try to do the same thing to a VM in the 10.50.0.0 segment. It will sit and spin, and then eventually error out and no connection made. If I go to File Explorer, Right click on MY PC and Map a network drive there, and put a check in the box for using a specific account….. I put in the user account info, hit enter….it attempts to connect, and then fails. Times out. No connection made.

Side note…similar issue occurred when attempting to RDP from 10.54.0.0 segment to 10.50.0.0 segment. But no issues when going to the 10.51.0.0 segment. Again cause I think the DC is on this segment. So to get around that issue, I had to disable NLA in the registry for the VMs that are sitting on the 10.50.0.0 segment.

Any ideas or thoughts as to why this is failing?

We have a similar setup on-prem now, where one segment has no DCs on it, and must authenticate against the DCs that sit on the other segment. But I have no issues mapping drives.

Thanks,