Article ID: 902160 - View products that this article applies to.
You intermittently cannot connect to a Web site that is hosted on Microsoft Internet Information Services (IIS) 6. When this behavior occurs, you may receive an error message that is similar to the following:
This behavior occurs if the following conditions are true:
HTTP Error 401 - Unauthorized: Access is denied due to invalid credentials.
The NTLM protocol that is used for Integrated Windows authentication requires a two-step process to authenticate clients. The behavior that is mentioned in the "Symptoms" section occurs when the following conditions are true:
To work around this behavior and to reduce the frequency of these error messages, configure the application pool to recycle less frequently. To configure application pool recycling, follow these steps:
For more information about how to use application pool recycling, visit the following Microsoft Web site:
http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/18b3a3cd-ff5f-4a48-bc63-810be04b131d.mspxFor more information about how IIS authenticates browser clients by using Windows Integrated authentication, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/264921/ )How IIS authenticates browser clients