There many possibilities, but you would be best served by opening a case with EMC Support where you would be provided a timely resolution to your issue.
Recently the network recieve a new IP range. We had to change not only the IP information but for some reason we had to rename the EMC system according to a EMC technician who helped walk us through the process. Everything seemed to work out fine for this last week. However the Windows server 2003 Domain controller which is hosting DNS, needed a reboot and we lost connectivity to the EMC NS600's shares. I am able to putty into the system, I am able to winscp and retrieve a SPcollect. I am still seeing the system in Active directory. However when I go to map a network drive I recieve a error that states  " {\\emcsharename} is not accessible. you might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permissions.  Could not find a domain controller for this domain."  The last part got me thinking that a little more information is needed. During the change the PDC went down for good, I have assumed FSMO roles on another server 2003 DC and when I do a dcdiag it shows only a time error, the times of the systems (emc, and servers and workstations) are still with-in one minute of eachother. I am able to connect to the domain and share between microsoft and other Unix devices.  If anyone could give me a brief walk through, trouble shooting help, or some advice it would be great. I am a 99% windows Admin and I am learning as I go.  Thanks in advance.
How to setup emc to map shares with a windows environment