Hi
Maybe the following will be helpful.
Resolution:
==========
This could be because there are multiple clients trying to access the same
server across a NAT device. The source IP addresses from all clients will
be the same as the NAT device which causes problems on the server.
Apply the following post-SP2 Windows 2000 hotfix to address this issue:
Q301673 - SMB Server Does Not Allow More Than 1 Client Connection Over NAT
http://support.microsoft.com/default.aspx?scid=kb;en-us;301673
You Cannot Make More Than One Client Connection Over a NAT Device
SYMPTOMS
=========
When two client computers try to use the server message block (SMB)
protocol to connect to the same server across a network address translation
(NAT) device, the more recent client connection may reset the earlier
client connection. If a client and a server that use the SMB protocol over
a NAT device are copying files, that session may be reset when another
client uses the SMB protocol over the same NAT device to the same server.
Note This problem does not occur when the server is running Microsoft
Windows NT 4.0.
CAUSE
=====
When a new connection is established to a server, the server checks for
previous connections from the same client IP address and deletes any
previous connections. Because NAT acts as a proxy for the SMB protocol by
using the same IP address from the two client connection requests, the
earlier connection is terminated.
RESOLUTION
==========
To resolve this problem, obtain the latest service pack for Windows 2000.
For additional information, click the following article number to view the
article in the Microsoft Knowledge Base:
260910 How to Obtain the Latest Windows 2000 Service Pack
The English version of this fix has the file attributes (or later) that are
listed in the following table. The dates and times for these files are
listed in coordinated universal time (UTC). When you view the file
information, it is converted to local time. To find the difference between
UTC and local time, use the Time Zone tab in the Date and Time tool in
Control Panel.
Date Time Version Size File name
----------------------------------------------------------
09-Aug-2001 17:35 5.0.2195.4110 1,685,696 Ntkrnlmp.exe
09-Aug-2001 17:35 5.0.2195.4110 1,685,312 Ntkrnlpa.exe
09-Aug-2001 17:36 5.0.2195.4110 1,705,984 Ntkrpamp.exe
09-Aug-2001 17:34 5.0.2195.4110 1,663,424 Ntoskrnl.exe
09-Aug-2001 17:34 5.0.2195.4110 237,104 Srv.sys
09-Aug-2001 17:37 5.0.2195.3805 73,488 Srvsvc.dll
STATUS
=======
Microsoft has confirmed that this is a problem in the Microsoft products
that are listed at the beginning of this article. This problem was first
corrected in Windows 2000 Service Pack 3.
MORE INFORMATION
=================
This fix applies only to the SMB protocol traffic over TCP NetBIOS port
139. The connectivity problem that is mentioned in this article still
occurs on client computers that are running Windows 2000 or later if you
make the connection with direct hosting on port 445. By default, Windows
2000 uses this port.
You can establish no more than one direct hosting client connection across
a NAT device. If you must have more than one simultaneous SMB protocol,
disable either direct hosting on the Windows 2000 file server or on all
clients behind the NAT device.
To disable direct hosting on the server:
1. Start Registry Editor.
2. Locate and then click the following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NetBT\Parameters
3. Add the following registry value:
Value Name: SmbDeviceEnabled
Type: REG_DWORD
Value Data: 0
The default setting is 1 (enabled)
When you complete these steps, clients must use port 139 NetBIOS over
TCP/IP to make a connection.
Note To permit multiple connections over the NAT device, Microsoft
recommends that you use Web Distributed Authoring and Versioning (WebDAV).
With this technology, you can perform standard file operations on a remote
share. For additional information about how to install Windows 2000 and
Windows 2000 hotfixes at the same time, click the article number below to
view the article in the Microsoft Knowledge Base:
249149 Installing Microsoft Windows 2000 and Windows 2000 Hotfixes
The information in this article applies to:
o Microsoft Windows 2000 Server SP1
o Microsoft Windows 2000 Server SP2
o Microsoft Windows 2000 Advanced Server SP1
o Microsoft Windows 2000 Advanced Server SP2
o Microsoft Windows 2000 Professional SP1
o Microsoft Windows 2000 Professional SP2
Or apply Windows 2000 SP3 on the server
Shilpa Sinha
This posting is provided "AS IS" with no warranties, and confers no rights.