File Sharing Operations to a Share on Local Computer May Be Slow

ID: Q231790

The information in this article applies to:

Microsoft Windows NT Workstation version 4.0
Microsoft Windows NT Server version 4.0

SYMPTOMS

When you share files on a computer, and then connect to that sharepoint from the same computer, file operations such as XCOPY may be slow if TCP/IP is the protocol being used.

CAUSE

If for example you share out a directory named "test", and then connect to that share from the same computer it was shared from, the TCP/IP stack uses what is called the "loopback" interface. The use of the "loopback" interface is to prevent packets between the client and server (which are on the same computer) from actually being sent out on the network cable.

TCP/IP implements "nagling" and "delayed acknowledgment", even though the interface in this case is loopback. This can cause unnecessary delays.

More details on nagling are available in ftp://ftp.microsoft.com/bussys/winnt/winnt-docs/papers/tcpipimp2.doc

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update. For information on obtaining the latest service pack, please go to:

http://www.microsoft.com/Windows/ServicePacks/

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

For information on obtaining the individual software update, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://www.microsoft.com/support/supportnet/overview/overview.asp

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was first corrected in Windows NT 4.0 Service Pack 6.

Additional query words: 4.00

Keywords : kbbug4.00 kbfix4.00
Version : winnt:4.0
Platform : winnt
Issue type : kbbug