We operate an iXSystems X9SCL NAS in the office and have since last year been normally accessing its network shared folders via SMB. Our Windows 10 computers were only Azure AD-registered with our Office/Microsoft 365 user accounts.
This year we've eventually gotten everybody's computers joined to Azure AD and enrolled to MDM. Brand new computers allocated are provisioned with Windows Autopilot; I got one such new laptop. With this new computer I found it impossible to access the shared folders; Windows credential prompt keeps popping up even though I keyed in the appropriate credentials. Doesn't matter if I pre-insert the credentials in Credential Manager.
I subsequently set the FreeNAS SMB service to log events; turns out this copy of Windows wants to access the IPC$ share instead of actual shared folder path.
[2020/07/06 19:15:27.580527, 2] ../../source3/auth/auth.c:316(auth_check_ntlm_password)
check_ntlm_password: authentication for user [user] -> [user] -> [user] succeeded
[2020/07/06 19:15:27.592802, 1] ../../source3/smbd/smb2_tcon.c:234(smbd_smb2_tree_connect)
smbd_smb2_tree_connect: reject request to share [IPC$] as 'NAS\user' without encryption or signing. Disconnecting.
Windows client side the SMBClient event log also indicates the same behaviour
Log Name: Microsoft-Windows-SmbClient/Security
Source: Microsoft-Windows-SMBClient
Date: 6/7/2020 19:57:04
Event ID: 31010
Task Category: None
Level: Error
Keywords: (256)
User: N/A
Computer: AADJ-LAPTOP
Description:
The SMB client failed to connect to the share.
Error: {Access Denied}
A process has requested access to an object, but has not been granted those access rights.
Path: \NAS\IPC$
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-SMBClient" Guid="{GUID}" />
<EventID>31010</EventID>
<Version>0</Version>
<Level>2</Level>
<Task>0</Task>
<Opcode>0</Opcode>
<Keywords>0x200000000000100</Keywords>
<TimeCreated SystemTime="2020-07-06T11:57:04.171064900Z" />
<EventRecordID>483</EventRecordID>
<Correlation />
<Execution ProcessID="4" ThreadID="3536" />
<Channel>Microsoft-Windows-SmbClient/Security</Channel>
<Computer>AADJ-LAPTOP</Computer>
<Security />
</System>
<EventData>
<Data Name="Reason">12</Data>
<Data Name="Status">3221225506</Data>
<Data Name="ShareNameLength">10</Data>
<Data Name="ShareName">\NAS\IPC$</Data>
<Data Name="ObjectNameLength">0</Data>
<Data Name="ObjectName">
</Data>
</EventData>
</Event>
Asked in TechNet forums but yet to obtain any insightful information regarding this behaviour.
The very same laptop has no problem accessing my home Synology DS NAS (although in this case, Windows oddly never prompts for credentials and instantly fails authentication, forcing pre-inserting credentials in Credential Manager to solve the problem). So it seems like some weird server-client combo problem. Have any other Windows client users encountered same problems of this network?
This year we've eventually gotten everybody's computers joined to Azure AD and enrolled to MDM. Brand new computers allocated are provisioned with Windows Autopilot; I got one such new laptop. With this new computer I found it impossible to access the shared folders; Windows credential prompt keeps popping up even though I keyed in the appropriate credentials. Doesn't matter if I pre-insert the credentials in Credential Manager.
I subsequently set the FreeNAS SMB service to log events; turns out this copy of Windows wants to access the IPC$ share instead of actual shared folder path.
[2020/07/06 19:15:27.580527, 2] ../../source3/auth/auth.c:316(auth_check_ntlm_password)
check_ntlm_password: authentication for user [user] -> [user] -> [user] succeeded
[2020/07/06 19:15:27.592802, 1] ../../source3/smbd/smb2_tcon.c:234(smbd_smb2_tree_connect)
smbd_smb2_tree_connect: reject request to share [IPC$] as 'NAS\user' without encryption or signing. Disconnecting.
Windows client side the SMBClient event log also indicates the same behaviour
Log Name: Microsoft-Windows-SmbClient/Security
Source: Microsoft-Windows-SMBClient
Date: 6/7/2020 19:57:04
Event ID: 31010
Task Category: None
Level: Error
Keywords: (256)
User: N/A
Computer: AADJ-LAPTOP
Description:
The SMB client failed to connect to the share.
Error: {Access Denied}
A process has requested access to an object, but has not been granted those access rights.
Path: \NAS\IPC$
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-SMBClient" Guid="{GUID}" />
<EventID>31010</EventID>
<Version>0</Version>
<Level>2</Level>
<Task>0</Task>
<Opcode>0</Opcode>
<Keywords>0x200000000000100</Keywords>
<TimeCreated SystemTime="2020-07-06T11:57:04.171064900Z" />
<EventRecordID>483</EventRecordID>
<Correlation />
<Execution ProcessID="4" ThreadID="3536" />
<Channel>Microsoft-Windows-SmbClient/Security</Channel>
<Computer>AADJ-LAPTOP</Computer>
<Security />
</System>
<EventData>
<Data Name="Reason">12</Data>
<Data Name="Status">3221225506</Data>
<Data Name="ShareNameLength">10</Data>
<Data Name="ShareName">\NAS\IPC$</Data>
<Data Name="ObjectNameLength">0</Data>
<Data Name="ObjectName">
</Data>
</EventData>
</Event>
Asked in TechNet forums but yet to obtain any insightful information regarding this behaviour.

Windows attempts to connect to IPC$ on FreeNAS SMB service
social.technet.microsoft.com
The very same laptop has no problem accessing my home Synology DS NAS (although in this case, Windows oddly never prompts for credentials and instantly fails authentication, forcing pre-inserting credentials in Credential Manager to solve the problem). So it seems like some weird server-client combo problem. Have any other Windows client users encountered same problems of this network?