My macbook pro connects to some windows machines but not all

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My macbook pro connects to some windows machines but not all

Hello,

After upgrading my Macbook Pro from High Sierra to Mojave (10.14.3), I lost connectivity to some windows machines. I can connect to some Windows computers, but not all. From the Finder, I use Go->Connect to Server, smb://<hostname>/<directory>, which was working prior to the upgrade. All machines are in the same workgroup, network environment hasn't changed. I can ping all the machines in question. Any help is appreciated. Thanks.

Venu H

MacBook Pro 13", macOS 10.14

Posted on Jun 27, 2019 12:33 PM

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Answer 1

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Tesserax

Level 10

152,278 points

Jun 27, 2019 2:29 PM in response to spvhawk

What version of SMB are the Windows devices, that are affected by this, configured for? Also, which version of Windows are they running? For example, Windows 10 no longer supports SMB 1.0.

You can check which version of SMB is used:

For macOS: Enter the following command in the Terminal app: smbutil statshares -m /<path to mount> OR smbutil statshares -a
For Windows:
- C:\Windows\system32\dism /online /get-features /format:table | find "SMB1" OR
- Get-SmbConnection -ServerName <device name>
- Which version of SMB protocol are you using on your File Server - Microsoft TechNet

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Answer 2

spvhawk Author

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4 points

Jun 27, 2019 1:50 PM in response to spvhawk

Follow up to my question. The error I get when the connection fails to a given <hostname> is

I'm trying to connect as a "registered user" with a valid username and password for the windows computer(s). Thanks again.

Venu H

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Answer 3

spvhawk Author

Level 1

4 points

Jun 28, 2019 1:12 PM in response to Tesserax

Macbook is running SMB 2.1, Windows 7 machines are running SMB 2.0.

Should have done little more digging before posting the question. As I mentioned earlier, I was able to connect to all the Windows machines from the Macbook, but your question prompted to look at the Windows registry. For reasons that are confounding to me, SMB was suddenly disabled on the 2 machines I couldn't connect to from the mac. I enabled it and all shares are fine. Came across some discussions about a Windows update possibly causing this issue, but couldn't confirm it.

Thank you and many apologies for not debugging enough before reaching out.

Venu H

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Answer 4

Tesserax

Level 10

152,278 points

Jun 28, 2019 3:00 PM in response to spvhawk

No apologies are necessary, just wanted to make sure what your devices are running.

Apple has implemented SMB 3.xx since OS X 10.10 (Yosemite,) but supports the previous 1.x & 2.x versions, even with macOS Mojave. Note, using SMB 1.x is considered non-secure and should be avoided. Apple only relies on AFP for Time Machine backups to their Time Capsule.

Ref: Apple Shifts from AFP File Sharing to SMB2 in OS X 10.9 Mavericks - Apple Insider

Are all of these Windows devices running Windows 7? If so, I believe they can only support SMB 2.1.

The smbutil statshares -a command, run from the Mac, would identify what SMB protocol variants are available for communicating with a specific Windows File Share.

For example, in the following image, I ran this command with my Synology NAS mounted on my Mac's Desktop. Note the SMB_NEGOTIATE values indicating all three SMB protocol variants are available between my Mac (running Mojave) to the NAS. What was finally negotiated can be seen as: SMB_VERSION = SMB_3.02

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Answer 5

spvhawk Author

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4 points

Jun 28, 2019 4:03 PM in response to Tesserax

Thanks again.

Venu H

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My macbook pro connects to some windows machines but not all

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