Can't mount smb shares with 11.3

Question

Can't mount smb shares with 11.3

Hello,

After upgrading to macOS 11.3, I'm no longer able to mount smb shares from a Solaris server, running the version 11.4.

If look at the tcpdump output with Wireshark, I see an SMB "Negotiate Protocol Request" answered with a succesfull "Negotiate Protocol Response". Right afterwards an SMB2 "Negotiate Protocol Request" is sent, which the server replies with a "STATUS_INVALID_PARAMETER".

This happened after the upgrade to macOS 11.3. Older macOS clients can mount the network share without any problems as well the Linux and Windows clients. This seems to be clearly an error on the macOS side.

Having an enterprise support contract on my MacBook Pro, I've contacted Apple support. The support lady had absolutely no idea what I was talking about and didn't even know what SMB is. After talking with her for 30 minutes she was very happy when I said that it does not make any sense talking with her because we're not moving anywhere.

Clearly there has something changed with the macOS 11.3 SMB client, and it's not only the multichannel support. Looks like others are also affected, but I was not able to figure out what has changed.

Does anybody know how to fix or workaround this?

MacBook Pro

Posted on Apr 29, 2021 12:04 PM

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Answer 1

Top-ranking reply

dramirez1969

Level 1

60 points

May 25, 2021 8:22 AM in response to Toby Cockcroft

This is just an untried suggestion to consider:

[Workaround]

Go to MacOS Terminal and enter the two command lines:

echo "[default]" | sudo tee -a /etc/nsmb.conf

echo "protocol_vers_map=2" | sudo tee -a /etc/nsmb.conf

After MacOS reboot the fileshare was available again.

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Answer 2

Apr 30, 2021 8:20 AM in response to JoseMendezFromCH

I'm having a similar problem. I have a WD My Cloud drive that I can no longer connect to using SMB2.

When I do ⌘K and enter cifs://mycloud-vvc5ht/Public I can authenticate using guest but when I try smb://mycloud-vvc5ht/Public and try to use guest it just refuses and asks me to authenticate again.

Prior to upgrading to 11.3 this worked fine. I've also tested it on my wife's computer, which is not upgraded to 11.3, and she can connect fine using smb://mycloud-vvc5ht/Public

It seems that SMBv1 works but SMBv2/3 doesn't.

I've also used wireshark to inspect the connection and everything appears fine.

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Answer 3

Jun 2, 2021 12:48 PM in response to dramirez1969

That really helped. Thank you very much for the hint.

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