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The short question is how to check that a networked DOS6 (MS-DOS 6.22) machine loads its network and its shared drives OK. Both from within that machine and from another modern laptop (OSX or linux or ... windows-10) within the same intranet.

Here are the details:

I have an industrial machinery which is controlled by a PC with MS-DOS 6.22. `MS Network Client` is used to provide network capabilities such as shared drives. This machine is in the intranet with lots of windows-10 and my osx 10.8 laptop which I use to test as I do not want to mess with the office machines.

Communication (i.e. sending files) with the machine was via shared network drives from a windows 10 computer. It uses SMBv1 without passwords. That no longer works.

The DOS6 machine had `net share test=c:\test /full /yes` and the WIN10 would drop files onto that (i guess mapping was via `net use \\DOS6\test`). After April/2018 and MS windows-10 update 1803, this stopped working from WIN10 machine because SMBv1 is now disabled by default. Fine. Because the administrator does not want to enable SMBv1 I am seeking an alternative and right now I am trying to connect to DOS6 using `smbclient` in OSX 10.8. But this fails and I am trying to troubleshoot. But I do not know how.

Remotely it does ping. Also, by using `nmap` I found out that port 139 is opened (NetBIOS) but port 445 (SMB) is closed (after checking locally and `net share` reports shared drives available.

I have also observed that after an `nmap` from within the same intranet, the DOS6 machine no longer pings. Could that mean a weird intranet wide/router/hardware firewall is blocking it? Can it be that DOS6 network stack crashes from `nmap`? How can I troubleshoot the latter? How can I see that the network drivers are alive and loaded. How can I see what ports DOS6 machine exposes from within it? How can I verify locally that it does share a drive.

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    Having that ancient machine on the same network as your office computers seems like a bad idea. Anyway you probably can't connect to it with a modern device. You probably need keep a VM running an older linux/windows. – Zoredache Jan 8 at 19:53
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    WHAT YEAR IS IT?! – Aaron Copley Jan 8 at 19:54
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    @Aaron, ObXKCD – Harry Johnston Jan 8 at 19:57
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  • good point! we only needed gunpowder and not nuclear power. All the motors and the actuators and the lasers are controlled by industrial logic boards which rely for comms and IO on some PC. If the manufacturers were as good IT designers as mechanical they would have used a tiny Linux and get over with it. They used something tiny OK but I guess obsolecense in mechanics timescale measures a tenth of what it is in IT timescale. The internal combustion engine is 120 years today? Btw the problem started with MS spreading SMBv1 like a virus and when all were addicted it killed it a la Mort Subite! – bliako Jan 8 at 21:49
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It's terrible when your vendor doesn't support a modern operating system and you have to run a business critical application on something old and crummy. Ugh.

I suspect that your nmap is upsetting an IDS and the traffic is being blocked mid-scan. Back in the day, I used to manually load drivers on the DOS system to test them and watch for errors. That might be a good debug for you.

The DOS6 machine had net share test=c:\test /full /yes and the WIN10 would drop files onto that (i guess mapping was via net use \\DOS6\test). After April/2018 and MS windows-10 update 1803, this stopped working from WIN10 machine because SMBv1 is now disabled by default. Fine. Because the administrator does not want to enable SMBv1 I am seeking an alternative and right now I am trying to connect to DOS6 using smbclient in OSX 10.8. But this fails and I am trying to troubleshoot. But I do not know how.

I don't blame the administrator for not wanting to enable SMBv1. Sorry.

I think this is going to come down to how important your industrial machinery app is. Perhaps they can do some network magic that only allows SMBv1 between the horrible (sorry) MSDOS machine and the Windows 10 machine. Unfortunately, I think you're going to have to get "buy in" on your app in order to get other people to support it.

I assume you've checked to see if the app supports a modern operating system? That would be the best solution, if the vendor allows it. Short of that, I think you're going to have to do some network contortions in order to find a way to run it (relatively) securely.

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    thanks for your reply. It is an expensive steelbeam drill and saw. Barely 20 years old. does the job fine. I suspect a lot of machinery are in this state today. It's a ferrari with a steering lever instead of a wheel! I suspected some network monitor might be at work there, thanks for pointing to IDS. – bliako Jan 8 at 21:38
  • After extensive troubleshooting I can report my findings. Connecting the machine and my OSX laptop via a hub (2 machines only network) does not solve any problem. So I can exclude IDS blocking some packets. I have tried using smbclient, curl and smbmap.py Nothing works except pinging the machine. What I noticed is that the machine has only 1 port opened after running MSCLIENT and net share, net use etc. This is 139. While port 445 is closed. I am not SMB expert at all. But is any SMB version operating without the use of port 445? Otherwise why port 445 is closed on the DOS machine? – bliako Jan 11 at 13:44
  • A thought occured to me: why not use my own file transfer application? Bingo. It will be secure (password access, client IP check), it will be as flexible as I want. MOST IMPORTANTLY: Eliminate Microsoft introducing bugs and security holes as regularly as a locust pandemic. I now have my own file transfer program installed on MSDOS 6.22 and can access it from OSX, Linux (and Windows) and even from an Android phone. Keep cool and avoid M$ at all costs even if it means doing extra brain work. THANKS! NO thanks to those who closed this question. Hacking coolness is difficult to achieve for some ! – bliako Jan 11 at 13:50

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