Article: Q297210
Product(s): Internet Information Server
Version(s): 4.0,5.0
Operating System(s):
Keyword(s):
Last Modified: 13-JUN-2001
-------------------------------------------------------------------------------
The information in this article applies to:
- Microsoft Internet Information Server versions 4.0, 5.0
-------------------------------------------------------------------------------
SYMPTOMS
========
When you use frameset pages on a site that uses NT Challenge Response as the
only authentication method, 401 errors may appear in the IIS logs during the
user's session. The user can successfully access the file shortly after the
errors occur, and may experience slight delays in accessing some files.
CAUSE
=====
When Microsoft Internet Explorer attempts to open a page that is divided into
multiple frames, it requests the different frames pages simultaneously on
separate ports. IIS sees these as separate requests because they are coming in
on separate ports, and requires each request to be authenticated individually.
MORE INFORMATION
================
This is by design for security reasons. Allowing the subsequent sockets to be
opened without requiring authentication first leaves the server open to attack.
Additional query words: IIS IE 401 frame NTLM
======================================================================
Keywords :
Technology : kbiisSearch kbiis500 kbiis400
Version : :4.0,5.0
Issue type : kbprb
Solution Type : kbpending
=============================================================================