Symptoms
Accessing shares hosted on a third party file server (such as NetApp or Dell EMC) from Windows server 2012 returns an error:
Windows cannot access \\ServerName
Cause
With Windows Server 2012 and Windows 8, Secure dialect negotiation is introduced in Server Message Block (SMB) 3.0. This feature depends upon the correct signing of error responses by all SMBv2 servers, including servers that support only protocol versions 2.0 and 2.1. Some third-party file servers do not return a signed error response. Therefore, the connection fails.
Resolution
Address this issue from the Windows Server end by either of the following methods:
Method 1:
Configure the following registry value on Windows Server 2012:
Key: HKLM:\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters
Value Name: RequireSecureNegotiate
Value Type: DWORD
Value Data: 0
Method 2:
Run the Powershell command:
Set-ItemProperty -Path HKLM:\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters RequireSecureNegotiate -Value 0 Force
Method 3:
Run the Powershell command cmdlet:
Set-SmbClientConfiguration RequireSecureNegotiate 0