Microsoft KB Archive/195179

= Cannot Disable HTTP KeepAlives for HTTP/1.1 Clients =

Article ID: 195179

Article Last Modified on 6/23/2005

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APPLIES TO


 * Microsoft Internet Information Server 4.0

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This article was previously published under Q195179



We strongly recommend that all users upgrade to Microsoft Internet Information Services (IIS) version 6.0 running on Microsoft Windows Server 2003. IIS 6.0 significantly increases Web infrastructure security. For more information about IIS security-related topics, visit the following Microsoft Web site:

http://www.microsoft.com/technet/security/prodtech/IIS.mspx



SYMPTOMS
HTTP/1.1 client connections are not closed, even if the Allow HTTP KeepAlives check box is not selected in the Web site's properties in Microsoft Management Console (MMC).



CAUSE
This behavior occurs because the Allow HTTP KeepAlives check box applies only to HTTP/1.0 clients that connect to the IIS server.



RESOLUTION
This behavior is by design.



MORE INFORMATION
The "Section 8.1.2.1 Negotiation" section of RFC2068 states the following:

In case the client does not want to maintain a connection for more than

that request, it SHOULD send a Connection header including the

connection-token close.

Sections 8.1.2.1 and 19.7.1 both discuss backwards compatibility for previous HTTP versions and state that persistent connections must be explicitly negotiated.

The AllowKeepAlives feature is only valid in the following scenarios:

If you clear the Allow HTTP KeepAlives check box on the server and use an HTTP/1.0 client that tries to establish a persistent connection, the server sends a close.

If you select the Allow HTTP KeepAlives check box on the server and use an HTTP/1.0 client that tries to establish a persistent connection, the server honors the request for persistence.

Keywords: kbprb KB195179

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