Windows cannot access SMB folder

Question

I have two Windows 11 computers and a Synology NAS. One of the computers can access the NAS's SMB folder, while the other cannot. I've conducted the following analysis and hope someone can help point out the issue:

1. I can access the SMB folder from the other computer, which indicates that my procedure is correct.
2. Neither of the computers has SMB V1 enabled, and since one of the computers can connect, it suggests that the SMB version is not the issue.
3. When I access the SMB folder from the successful computer, a window automatically prompts me for a username and password. However, the other computer displays "Windows cannot access \ip\share" before reaching this step, which suggests that login credentials are not the problem.
4. Both computers and the NAS have their firewalls enabled without any special configuration. Additionally, both computers can connect to the NAS via SSH and ping, indicating that the firewall is likely not the issue.
5. Both computers have the same Network security: LAN Manager authentication level :Send NTLMv2 responses only. Refuse LM & NTLM

These are the solutions and corresponding attempts I've gathered from online resources. Is there anything I might have overlooked?

Answer 1

Hello,

Based on the information provided, here are a few additional troubleshooting steps you can try to check the issue:

Check Network Discovery and File Sharing settings: Ensure that Network Discovery and File Sharing are enabled on both Windows 11 computers. You can find these settings in the Network and Sharing Center or the Windows Settings.

Confirm IP address and DNS settings: Double-check that both computers have valid IP addresses and their DNS settings are properly configured. Incorrect IP or DNS settings can sometimes cause issues with SMB access.

Verify network connectivity: Confirm that both computers and the NAS are on the same network segment and can communicate with each other. Use the “ping” command to check network connectivity between the computers and the NAS.

Try accessing the NAS using its IP address: Instead of using the hostname to access the NAS, try accessing it using its IP address (e.g., \192.168.1.100\share). This can help identify if there is an issue with name resolution.

Check NAS permissions: Ensure that the SMB folder on the NAS has the appropriate permissions configured, allowing access to both Windows 11 computers. Double-check the share permissions and the security permissions on the folder.

Disable any third-party antivirus or security software: Temporarily disable any third-party antivirus or security software on the computer that cannot access the SMB folder. Sometimes, these software can interfere with SMB connections.

Enable SMB logging: Enable SMB logging on the NAS to gather more detailed information about the connection attempts.

Best Regards,

Hania Lian

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