HTTP Keep-Alive header sent whenever ASP Buffering is enabled

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Article ID: 238210 - View products that this article applies to.
This article was previously published under Q238210
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SYMPTOMS

Whenever ASP Buffering is enabled, either through the Microsoft Management Console (MMC) or programmatically in the Active Server Pages (ASP) page (response.buffer=true), an HTTP Keep-Alive header will be sent along with the Content-Length.

Note This problem occurs only on HTTP 1.0 clients. An HTTP Keep-Alive header is not sent for HTTP 1.1 clients. In communications between HTTP 1.1 clients and HTTP 1.1 servers, the Keep-Alive header is implied, so the header is not actually sent.

CAUSE

This is by design.

WORKAROUND

The header can be disabled by adding the following code to the top of the ASP pages:
<%response.flush%>
				

MORE INFORMATION

This behavior occurs even if Keep-Alives are disabled in the MMC. The Keep-Alive will be ignored by HTTP 1.0 (browser) clients. HTTP 1.0 Proxies will require the Content-Length header to also be present. This is transmitted by default but could be modified by an Internet server application programming interface (ISAPI) filter. If a filter is used and the Content-Length is not sent, then you will have to implement the workaround described above.

Properties

Article ID: 238210 - Last Review: February 28, 2014 - Revision: 5.1
APPLIES TO
  • Microsoft Internet Information Server 4.0
  • Microsoft Internet Information Services 6.0
  • Microsoft Internet Information Services 5.0
Keywords: 
kbnosurvey kbarchive kbpending kbprb KB238210

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