samba - Apr 2024 - Ancient SMB client issues

I have a customer with a couple of industrial robots running Linux 2.6.34 and
Samba 3.4.7 (smbclient -V). They are able to connect to SMB shares on Windows
servers IF I "allow unsafe connections?, ie lower the SMB minimum level.
The servers are on Windows 2019, and this setup has worked for a couple of years
now.

I have created a virtual Debian/Samba 4.19 server with the intention of moving
over the SMB shares that the robots need to this server. If I connect from
Windows 10 clients to the Samba servers shares, no issues. If I try the same
from the robot (ancient SMB) then it fails with the rather bleak ?protocol
negotiation failed: NT_STATUS_INVALID_NETWORK?. I get this error regardless of
the min protocol level (NT1 or SMB2) on the server.

In short, are we doomed to stay with the unsafe Windows share connections, or is
there another way to migrate from Windows to Linux? Maybe running an ancient
Samba too, but that does not sound too attractive?

On Thu, 11 Apr 2024 14:38:51 +0200
Anders ?stling via samba <samba at lists.samba.org> wrote:
> I have a customer with a couple of industrial robots running Linux
> 2.6.34 and Samba 3.4.7 (smbclient -V). They are able to connect to
> SMB shares on Windows servers IF I "allow unsafe connections?, ie
> lower the SMB minimum level. The servers are on Windows 2019, and
> this setup has worked for a couple of years now.
> 
> I have created a virtual Debian/Samba 4.19 server with the intention
> of moving over the SMB shares that the robots need to this server. If
> I connect from Windows 10 clients to the Samba servers shares, no
> issues. If I try the same from the robot (ancient SMB) then it fails
> with the rather bleak ?protocol negotiation failed:
> NT_STATUS_INVALID_NETWORK?. I get this error regardless of the min
> protocol level (NT1 or SMB2) on the server. 
> 
> In short, are we doomed to stay with the unsafe Windows share
> connections, or is there another way to migrate from Windows to
> Linux? Maybe running an ancient Samba too, but that does not sound
> too attractive?
You probably need three machines:

Your industrial robots that use SMBv1

A 'machine' in the middle with 'server min protocol = NT1' set
(it will
default to 'client min protocol = SMB2_02'

A Samba server that isn't using SMBv1

The robot can connect to and download files from the intermediate
machine, which in turn (without using SMBv1) can download from the
Samba server.

Rowland