sudo mount -t cifs //<dfs-url>/<service> ~/mountpoint/ -o username=<username>

smbclient //<dfs-url>/<service> -U <username> -W <workgroup>
Enter <username>'s password:
Domain=[<domain>] OS=[Windows Server 2012 R2 Datacenter 9600] Server=[Windows Server 2012 R2 Datacenter 6.3]
tree connect failed: NT_STATUS_BAD_NETWORK_NAME