Can't connect to NAS

Question

I upgraded workstation (new box on domain) from Windows 10 Pro to Windows 11 Pro. no changes to network configuration. reviewed a number of self-help scenarios but can't solve problem. NAS is still available from server and other workstations.

Need some suggestions

Thanks

Answer 1

Hello Todd Williams,

Has your issue been solved? If it has, please accept the answer so that it could be spread further to those in need too. If not, is there anything I can help you with? Please let me know. :)

VP

Answer 2

Hello Todd Williams,

Windows 11, particularly starting with version 24H2, enforces strict SMB security postures by mandating SMB signing and strictly blocking unauthenticated guest access, which is the most common reason NAS connectivity breaks after an OS upgrade.

According to Microsoft's official documentation regarding SMB security enhancements, Windows 11 Pro defaults to requiring SMB signing for all outbound connections to mitigate NTLM relay attacks. You can confirm exactly why Windows is dropping the connection by inspecting the Event Viewer under Microsoft-Windows-SmbClient/Operational. You will likely see Event ID 31017, which indicates the client rejected an insecure guest logon, or Event ID 31600, indicating a signing failure. To diagnose the exact policy enforcement, inspect the registry path at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters. The REG_DWORD values RequireSecuritySignature and AllowInsecureGuestAuth govern this behavior. While you could technically alter these values via PowerShell using Set-SmbClientConfiguration -RequireSecuritySignature $false to force a connection, Microsoft explicitly dictates that doing so leaves the workstation vulnerable to credential theft. The only officially supported, permanent resolution is to configure the NAS management interface to disable guest access and mandate SMB signing. Additionally, you must verify via secpol.msc that your domain's Network Security: LAN Manager authentication level policy is set to Send NTLMv2 response only, as Windows 11 will outright reject legacy NTLMv1 handshakes from the NAS.

Hope this answer brought you some useful information. If it has, please consider accepting the answer so that other people sharing the same issue would benefit too. Thank you :)

VP

Answer 3

If you are unable to connect to your NAS after upgrading from Windows 10 Pro to Windows 11 Pro, here are some suggestions to troubleshoot the issue:

1. Check Network Configuration: Ensure that the network settings on your new workstation are correctly configured. Verify that the workstation is connected to the same network as the NAS and that it has the appropriate IP address settings.
2. Firewall Settings: Check the firewall settings on your Windows 11 workstation. Sometimes, the firewall may block access to network resources. You can temporarily disable the firewall to see if it resolves the issue.
3. Network Profile: Ensure that your network profile is set to "Private" rather than "Public". A public profile may restrict access to network devices.
4. SMB Protocol: Verify that the SMB (Server Message Block) protocol is enabled on your Windows 11 workstation. Windows 11 should have SMB1 disabled by default, but if your NAS requires it, you may need to enable it through Windows Features.
5. Credentials: Make sure you are using the correct credentials to access the NAS. Sometimes, after an upgrade, saved credentials may not work as expected.
6. DNS Resolution: Ensure that your workstation can resolve the NAS's hostname. You can test this by pinging the NAS from the command prompt.
7. Event Viewer: Check the Event Viewer for any error messages related to network connectivity or file sharing that may provide additional insights into the problem.
8. Mapped Drives: If you had mapped drives to the NAS, try disconnecting and remapping them after the upgrade.

If the problem persists, consider testing the connection with another device to isolate whether the issue is specific to the new workstation or a broader network issue.

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References:

• Domain-joined machines can't detect the domain profile
• Troubleshoot networking errors that occur when you join Windows-based computers to a domain