Compression Is Not Enabled on POST Request (259760)

The information in this article applies to:

Microsoft Internet Information Services 5.0

This article was previously published under Q259760

SYMPTOMS

HTTP compression allows Internet Information Services (IIS) to send compressed content to the browser when the following conditions are true:

The HTTP request is issued by a compression-enabled browser.
HTTP Compression is enabled on the IIS server for static and/or dynamic content.
The request is an HTTP GET request.

Even when you enable HTTP Compression, POST responses are not compressed.

CAUSE

This is a design limitation in IIS 5.0. A fix has been developed to enable HTTP Compression on POST requests. See the "Resolution" section for more information.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

The English version of this fix should have the following file attributes or later:

   Date        Time    Version       Size    File name     Platform
   -------------------------------------------------------------
   04/13/2000  10:16p  5.0.2195.2037 23312   Compfilt.dll  i386<BR/>

STATUS

Microsoft has confirmed that this is a problem in Internet Information Services 5.0. This problem was first corrected in Windows 2000 Service Pack 2.

MORE INFORMATION

To enable HTTP compression on POST requests, do the following:

Enable HTTP Compression (see the IIS documentation for information on how to do this.)
Install the fix.

Set the EnablePostCmp registry parameter to 1:

   EnablePostCmp
   Key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\W3Svc\Parameters
   Value Type: REG_DWORD - Boolean
   Valid Range: 0,1 (False or True)
   Default: 0 (False)
   Description: Setting this parameter to 1 causes compression to be enabled also on POST.

Modification Type:	Minor	Last Reviewed:	9/23/2005
Keywords:	kbHotfixServer kbQFE kbbug kbfix KB259760