Snapdrive RPC Error connecting to Netapp from Windows Server 2012

When you try to connect to a Netapp storage from a newly installed Windows 2012 Server you may run into this misleading error. Snapdrive reports that the Storage system is not reachable even though basic networking (ping and nslookup) works.

 

netapp_rpc_errorYou can see the same error (actually a different error, but it is caused by the same problem) when trying to access the hidden c$ share on your netapp via <netapp_name>c$

This error is caused by the new SMB3 protocol in Windows 8 and Windows Server 2012 which requires signed answers even on older SMB versions!
This signing is not activated per default on the Netapp Filers (maybe this will change when Windows 2012 gets more wide spread), but it can easily be enabled at the Console with

options cifs.smb2.signing.required on

More info on this here and here.