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GetCool

Is it possible to break SMB *client* functionality?

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I'm wondering if I removed something with nLite that actually broke SMB functionality entirely. Note that I'm referring to accessing SMB shares, not using my machine as an SMB server.

I have a heavily stripped-down Windows XP Pro install; I cannot provide the exact configuration at the moment, but I do know that I removed all the available services and networking components.

This configuration has worked fine for my needs, but I just recently set up a Samba server in my home, and now I can't access any of the Samba services from my Windows machine. Specifically, when I try to enter any UNC in Explorer (either \\hostname or \\ip.address), I immediately get a message about the address not being found (even with the server's hostname in my hosts file, etc.).

Of course, it could be a Samba configuration problem as well (as I don't have another machine to test), but I have a lot of experience with Samba, and given the simplicity of this particular implementation (a single share), I am inclined to believe that it's fine.

Anyway, I was hoping someone could tell me if there is a known way to remove SMB client functionality with nLite, since I don't remember any of the item descriptions stating as such.

Thanks.

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Absolutely possible.

Maybe you removed a needed protocol.

Do you remember having use the option not to install default network components ?

And there's also the "Close Microsoft-DS port" tweak which seems to have some side-effects.

We'd really need your lastsession.ini

Warning : what follows is not 100% guaranteed, I've not been able to find a good place explaining SMB implementation in Windows quickly and in an understandable way.|

(that's why I want to setup a group of 5 VMs and study how they communicate between each others)

Port 445 is used in 2k, XP and 2k3.

This tweaks is pretty weird because it seems to prevent you from using Network Drives.

However, network drives existed before port 445 (as far as I remember, at school we have some computers to conducts experiments in biology and they run 95/98 and use network drives).

In theory if port 445 can not be accessed windows should use ports 139/138/135. This is a typical situation when accessing SMB shares on a win9x computer from win2K and higher.

I don't think Samba has problems but I think this "Close Microsoft-DS" tweak has side-effects.

It's also possible it has something to do with a Netbios over TCP/IP (not sure about the exact name), which handles port 445 afaik.

But this is unlikely since the use of port 445 was a surprise to Samba devs : I don't think Samba would require it even if your computer is XP.

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Maybe you removed a needed protocol.

Do you remember having use the option not to install default network components ?

And there's also the "Close Microsoft-DS port" tweak which seems to have some side-effects.

Well, I don't have access to my LastSession.ini at the moment, but I'm looking through the options in nLite right now, and I can say that I'm pretty sure I removed all the networking components, operating system components (save for a few command-line tools), and services that are available to be removed (on WinXP Pro SP2).

However, looking through them, I can't see anything that suggests it would break SMB client functionality. The closest things I can see are:

  • The TCP/IP NetBIOS Helper service, which disables NetBIOS over TCP/IP (NetBT). I can personally attest, however, that NetBT is not needed on a network that does not use NetBIOS. I have successfully connected to SMB shares (both Samba and Windows 2003) from a machine with this service disabled, when the networks used straight DNS for name resolution.
  • The Map Network Drives/Network Places Wizard OS component. This shouldn't be necessary with the net use command. Furthermore, I haven't even gotten to the point of trying to map a drive; simply entering a UNC in Explorer doesn't work.

That leaves, of course, the "Close Microsoft-DS port" tweak, which I know that I did enable. I would think that this would do just what it suggests--close inbound TCP port 445--but perhaps it has other consequences.

I have successfully set up a Samba server in the past with only TCP port 445 open to the server. No NetBT, no 137-139, etc.; and Windows XP clients could connect to the shares just fine (using DNS for name resolution).

I agree that SMB on Windows is confusing... every time I think I understand it, there's a new angle I dig up. Nonetheless, theoretically speaking, nothing on my network is such that it should break communication between my client and server. Given that, the problem most likely exists on the client itself, which points to an issue with my nLite configuration.

I think reverting that one tweak is worth a shot. It will be interesting to see what it does.

Edited by GetCool

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The "close microsoft-ds port" tweak is not a good one imho. I'm not speaking of the way it is implemented in nlite but one the tweak itself.

To me it is just too stupid. It's like you want to prevent anybody from using your computer and you set your computer to run on 220Volts instead of the usual 110Volts (or the other way round for me).

From what I've seen it does not disable NetBT but breaks it by providing windows wrong informations.

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I haven't read the thread so sorry if I repeat.

Don't use Network section in the Tweaks.

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Don't use Network section in the Tweaks.

Nuhi,

While I am sure that disabling all of the Networking tweaks is a safe, blanket way to ensure SMB functionality, I'd still like to know exactly which tweak(s) cause the problem.

Looking over them again, it would seem that if you don't use NetBT, then all of the tweaks can be enabled except for the "Microsoft DS" tweak. Of course, this is just a hypothesis; I will disable this tweak through the registry and see if it works.

Edited by GetCool

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Port 445 is essential for SMB without NetBT

Yeah, and I can verify now that it is definitely the "Microsoft-DS" networking tweak that breaks SMB.

While I knew that closing port 445 would kill SMB, I always thought that this tweak just closed inbound port 445. Apparently it closes it outbound as well.

So, just to summarize: it is safe to use all of the networking tweaks, except for the port 445 / SMB tweak, provided that you don't care about NetBT and you're using DNS (or you're not using any name resolution at all, and just using plain IP addresses).

Edited by GetCool

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If it can help, LMHOSTS (or Samba NetBIOS hosts file) and SMB registry keys can be found here:

  • [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NetBT\Parameters]
    "EnableLMHOSTS"=dword:00000000
    "SMBDeviceEnabled"=dword:00000001

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