Article: Q288323
Product(s): Internet Information Server
Version(s): 4.0
Operating System(s):
Keyword(s):
Last Modified: 27-JAN-2002
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The information in this article applies to:
- Microsoft Internet Information Server version 4.0
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SYMPTOMS
========
After you install Microsoft Windows NT Server Service Pack 6a, Web Browsers, you
can receive the following error message:
HTTP 401.5
Unauthorized: Authorization failed by ISAPI/CGI app.
This error can occur when Internet Information Server (IIS) is set to require
Windows NT Challenge/Response on a Web site or virtual directory.
CAUSE
=====
HTTP Keep-Alives are required for Windows NT Challenge/Response to work
properly. If the HTTP Keep-Alives Enabled check box has been cleared, the IIS
metabase has not been updated with the correct setting, and therefore,
Keep-Alives are still enabled. Windows NT Challenge/Response continues to work
properly.
After you install Windows NT Server Service Pack 6a, the metabase setting is
corrected to match the HTTP Keep-Alives Enabled check box. Because Windows NT
Challenge/Response requires HTTP Keep-Alives, the now disabled setting prevents
Windows NT Challenge/Response from working correctly.
RESOLUTION
==========
1. In the Internet Services Manager, right-click the Web site for which you want
to enable Windows NT Challenge/Response, and then click Properties.
2. Click the Performance tab, and the click to select the HTTP Keep-Alives
Enabled check box.
3. Click OK.
MORE INFORMATION
================
For additional information on Windows NT Challenge/Response, click the article
number below to view the article in the Microsoft Knowledge Base:
Q102716 User Authentication with Windows NT
Additional query words: NTLM keep-alives sp6a AllowKeepAlive AllowKeepAlives
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Keywords :
Technology : kbiisSearch kbiis400
Version : :4.0
Issue type : kbprb
Solution Type : kbpending
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