Windows 7 – Troubleshoot Windows 7 to Mac SMB Share Rejection

macnetwork-sharessmbwindows 7

I have 4 machines, three Windows 7, one Mac Yosemite.

All happily share folders except one.

One Windows 7 machine can see all the others & connect to all PCs, but not the Mac.
Mac can see & connect to all Windows machines' shares.
All the other Windows machines can connect to the Mac shares.
RDC works between all machines.
Problem machine can connect to all other shares, just not the Mac.
Error is "Logon failure: unknown user name or bad password"
user/password is, of course, correct.

Same error for two different admin users, whether they are logged to their own account or 'swapping' credentials.
These users are admin on all machines on the network, with specific admin accounts.

So – suspect machine; I've run
sfc /scannow, no issues
tweaking.com's 'all-in-one' fixer, no issues.
Malwarebytes, no issues
Hitman Pro, no issues
adwcleaner, no issues
BitDefender [paid, on there always] no issues

I've checked, changed & reset correct Workgroup on suspect PC & Mac
Checked, changed & reset Mac's SMB shares [other machines correctly responded by being unable to find, then again find & connect to the resource]

I've checked that Services match one of the known-good machines.

Master browser is forced to my always-on server, which has been rebooted, but no other action.
Router is a nix Sophos UTM 9, but I don't think that's part of the problem.

What did I miss?

Best Answer

Figured it…

The Windows machine generates this error -
logon failure: unknown username or password OS X
& re-presents the login page. No amount of credential-checking/switching seems to work.

It appears that there is a Console error generated on the Mac at the same time as the Windows machine tries to connect -
od failed with 2 proto=ntlmv1-with-v2-session

Things to try...

  • (a) turn samba off and on again in sharing…

    System Prefs > Sharing > File Sharing > Options…

    enter image description here

  • (b) change the local security policy on your PC.

    1. Click Start
    2. Click Control Panel
    3. Click System and Maintenance
    4. Click Administrative Tools
    5. Double-Click Local Security Policy
    6. In the left pane, click the triangle next to Local Policy
    7. In the left pane, click Security Options
    8. In the right pane near the bottom, double-click "Network security: LAN manager authentication level"

    Then try one or both of these options. The 2nd worked for me.

    1. Click the drop-down box, and try either
      "Send LM & NTLM - use NTLMv2 session security if negotiated"
      or
      "Send NTLMv2 response only"
    2. Click OK

Sources:
https://discussions.apple.com/thread/6613032
http://www.jimmah.com/vista/net/ntlm.aspx

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