I cannot access a shared folder on my Synology NAS via SMB or AFP. What can I do?

I cannot access a shared folder on my Synology NAS via SMB or AFP. What can I do?

Symptoms

You cannot access a shared folder on your Synology NAS running DSM 6.0 or above via SMB or AFP protocol.

Resolution

On your Synology NAS

Confirm the following:

  1. Your Synology NAS and network connection are working properly.1
  2. Your Synology NAS and client computer are in the same LAN.
  3. Your Synology NAS is assigned a static LAN IP address and the firewall settings (DSM 7.0 / DSM 6.2) do not block the SMB (137-139, 445) or AFP (548) network ports.
  4. If you want to access your Synology NAS over the Internet, port forwarding rules must be configured correctly for SMB or AFP on your router.2
  5. Volumes have a Normal status.
    • DSM 7.0 and above: Go to Storage Manager > Storage > Storage Pool > Volume to view the volume status.
    • DSM 6.2 and below: Go to Storage Manager > Volume to view the volume status.
  6. The shared folder you want to access exists in Control Panel > Shared Folder. If the shared folder is encrypted, make sure that it is mounted.3
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  7. You have enabled SMB or AFP at Control Panel > File Services.
  8. The user account has the appropriate application privileges for SMB or AFP at Control Panel > Application Privileges (DSM 7.0 and above).
  9. Your user account has permission to access the shared folder.4
  10. If the guest is no longer needed, it must be disabled.5
    • DSM 7.0 and above: Go to Control Panel > User & Group > User to disable the guest account.
    • DSM 6.2 and below: Go to Control Panel > User to disable the guest account.
  11. In DSM 7.2 or above, go to Control Panel > Security > Protection. If Enable auto block is selected, click Allow/Block List. If any of your client computer's IPv4/IPv6 addresses are blocked, remove them from the Block List or add them to the Allow List.
  12. The maximum and minimum SMB protocol settings meet your client computer's requirements. You can set Maximum SMB protocol to SMB3 to ensure maximum SMB support, and set Minimum SMB protocol to SMB2 to enhance security.6
    • DSM 7.0 and above: Go to Control Panel > File Services > SMB > Advanced Settings to configure SMB protocols.
    • DSM 6.2 and below: Go to Control Panel > File Services > SMB/AFP/NFS > Advanced to configure SMB protocols.

On your client computer

After you have followed the instructions in the section above, try connecting to the shared folder via a Windows PC or Mac. If you have trouble connecting, check the following:

For Windows PC

For Mac

Notes:

  1. Refer to this article to resolve hardware or network connection issues.
  2. Exposing network ports to the Internet may have security risks. We recommend using a VPN to connect to your Synology NAS. If you must configure port forwarding rules to access your Synology NAS over the Internet via SMB, please do the following:
    • Set the Minimal SMB protocol to SMB2.
    • Set the Maximum SMB protocol to SMB3.
    • Set the Transport encryption mode to Force. Select Auto mode if your client computer does not support transport encryption.
  3. Windows File Explorer prevents the connection to shared folders with names ending in a dot (.) via UNC path. For example, connecting to “\\Server name of Synology NAS\Shared Folder Name.” will fail.
  4. Sign in to File Station with an account belonging to the administrators group (or ask an administrator) to check and adjust the shared folder permissions. Refer to this article for detailed instructions.
  5. If the guest account is enabled, your PC may automatically attempt to access the shared folder as a guest. This may result in access denial due to the lack of permissions. Untick the Enable Local Master Browser checkbox if you cannot disable the account. Then, try to disable the account again.
    • DSM 7.0: Go to Control Panel > File Services > SMB > Advanced Settings > Others to find the checkbox.
    • DSM 6.2: Go to Control Panel > File Services > SMB/AFP/NFS > Advanced Settings to find the checkbox.
  6. SMB3 is backwards-compatible with SMB2 and is more secure than SMB1. Please note the following:
    • SMB1 is disabled by default since Windows 10 version 1709. Set the minimum SMB protocol to SMB2 for Windows 10 PCs.
    • Some legacy operating systems and devices (e.g., Windows XP, multi-function printers, IP cameras, or network media players) only support SMB1. Refer to this article or consult the providers of your operating system/device for the minimum SMB protocol requirements. Then, you can make changes as needed in DSM.
    • If your Synology NAS is joined to an LDAP server that does not support Samba schema, set the maximum and minimum SMB protocols to SMB1 and tick the Enable CIFS plain text password authentication checkbox. Consult your LDAP service provider about Samba schema support if necessary.
      • DSM 7.0: Go to Control Panel > Domain/LDAP > Domain/LDAP > Edit > Advanced to find the checkbox.
      • DSM 6.2: Go to Control Panel > Domain/LDAP > LDAP to find the checkbox.
  7. Certain versions of Windows may behave differently when mapping network drives. If you are unable to map network drives when Windows Hello is enabled, try the following:
  8. Ping is a network utility that sends an echo request packet to an IP address and then waits for a reply. A successful ping will get a reply from the server and return the corresponding IP address of the server name. Ideally, no data packets should be lost and the round trip time should be short.
  9. To access the files stored on a domain-joined Synology NAS, sign in by adding "localhost\" before the local user name of the Synology NAS.
  10. Check the access permissions of the shared folder to see if one account type can access the folder but the other account type cannot.
  11. SMB NTLMv2 authentication process converts all lowercase letters with umlauts to their uppercase counterparts. However, Mac systems are unable to perform this conversion correctly, which leads to authentication issues.
Symptoms
Resolution
On your Synology NAS
On your client computer