Inconsistent SMB access via Win10. Could it be a DSM7 issue?

[dglp]

I've had a DS218 for a couple of years, pretty much problem-free. But this week, after an upgrade to DSM7, and a decision to reorganise large chunks of data, I've come up against two problems that have kept me from accessing the data. One is that I cannot get W10 to recognise a new shared folder. The other is that W10 blocks access to some of the older folders. It's doing my head in.

I have done all sorts of things on the Windows side, and resolved some of the mapping issues, and one of the access issues. I have 17 shared folders. Of those, W10 refuses to map one of them, refuses access to two others, and refuses to let me write to a fourth one. The other 13 shared folders seem to be working fine in terms of access. I have started messing around in DSM, and changing permissions, changing security settings, and so on. Pretty much anything I come across that looks like it might allow W10 to recognise or access those last few folders.

In contrast, I have fully functional access via Android apps. I have an Android phone with a combination of Syno and 3rd party apps that provide access. I have no difficulty getting into any folder on the NAS, and writing data to it. So the problem has to be something Windows related, but perhaps on the NAS side.

Can anyone help me make sense of this or outline ways of working through possible causes?

 

[Rusty]

SMB setting in the nas/dsm side are what atm?

 

[EAZ1964]

Similar posts have been made quite often, and you can find these on the forum.
Most of these were caused by the security default settings that were raised by synology (and sadly not by always by W10).
In addition to the question raised by Rusty, you might want to start at checking the NTLMV2 setting in W10.

 

[dglp]

Similar posts have been made quite often, and you can find these on the forum.
Most of these were caused by the security default settings that were raised by synology (and sadly not by always by W10).
In addition to the question raised by Rusty, you might want to start at checking the NTLMV2 setting in W10.

You nailed it instantly.

I was going through the steps outlined in this thread, and got things working after trying the NT/NTLM settings change.

So would you call this a Windows Authentication issue?
The bizarre things about it were the symptoms, which varied from folder to folder.

 

[EAZ1964]

Good to hear that you solved it.
Not sure to call it an authorization issue. It is a network security issue, that is raised to latest version of security in DSM 7, but kept on old settings in some W10 systems.
This simple update was not made consistently in the windows update cycle, not sure why, possibly a bad update.
It took Microsoft even 6 years to ban SMB1, everybody knew it was a huge risk, sloppy?

 

[Coop777]

these things are always a pain when they happen - DSM 7 turned off NTLMv1, which requires a change to an NTLM security policy on the windows client. Fun times!

 

[Gerard]

these things are always a pain when they happen - DSM 7 turned off NTLMv1, which requires a change to an NTLM security policy on the windows client. Fun times!

Hello I have a windows machine, when I checked my NTLM setting it’s blanked out; not set to anything. I have not had any issues like others have faced with mapping drives. What would make the windows machines so different with this setting?

 

[dglp]

Hello I have a windows machine, when I checked my NTLM setting it’s blanked out; not set to anything. I have not had any issues like others have faced with mapping drives. What would make the windows machines so different with this setting?

Which version of Windows? For example, I'm on W10 Pro version 21h2

 

[Gerard]

Which version of Windows? For example, I'm on W10 Pro version 21h2

W10 Pro 21h2

 

[Coop777]

Hello I have a windows machine, when I checked my NTLM setting it’s blanked out; not set to anything. I have not had any issues like others have faced with mapping drives. What would make the windows machines so different with this setting?

what setting did you check? there is an NTLM security policy that has to be changed.....

 

[Gerard]

what setting did you check? there is an NTLM security policy that has to be changed.....

The NTLM security policy for local computer, Network Security: LAN Manger authentication level. This is what those who are having trouble are changing to force NTLMv2

 

[dglp]

The NTLM security policy for local computer, Network Security: LAN Manger authentication level. This is what those who are having trouble are changing to force NTLMv2


View attachment 5574

So this is what I see:

 

[Gerard]

So this is what I see:

Right, so it puzzles me why I do not need to have this setting forced to NTLMv2, and SMB/drive mapping works for me with no issues. But others need to resort to going into the deep settings and have to tinker with these options just to get something to work.

 

[EAZ1964]

Are you on DSM7 Or still on 6?
is the SMB setting in your DS network advanced allowing for ntlmv1?

in both cases the issue will also not be there.

 

[Gerard]

Are you on DSM7 Or still on 6?
is the SMB setting in your DS network advanced allowing for ntlmv1?

in both cases the issue will also not be there.

Dsm7. Smb setting does not have ntlmv1 checked; so it’s off

 

[dglp]

Something, somewhere....
I wonder who knows.