Cannot upload large files to Microsoft Internet Information Server (IIS) 6.0 when using client authentication
2 years ago
Originally Published: 2005-09-02
Article Number
000057378
Applies To
Microsoft Internet Information Server (IIS) 6.0
Microsoft Windows Server 2003
Keon Certificate Authority 6.5.1
Issue
Cannot upload large files to Microsoft Internet Information Server (IIS) 6.0 when using client authentication
Microsoft Internet Information Services (IIS) logs show HTTP error 413 (Request Entity Too Large) when attempting to upload a document to the web server
Cause
The Web server has determined that the data being sent by the browser is simply too large (that is, too many bytes). This occurs when file size limits are exceeded. For example, when uploading a very large file (using a technique such as HTTP PUT), a 413 error may be returned when the web server sees that the file size is too large.
Resolution
This error is typically due to configuration errors on the web server. It may be possible to shrink the request entity (such as uploading a smaller file). Otherwise, the web server will need to be reconfigured to accommodate the larger entity.

Microsoft has forwarded additional documentation in regard to this error and the required fix. The IIS Metabase contains a file upload setting (UploadReadAheadSize). The UploadReadAheadSize property establishes the number of bytes a web server will read into a buffer by setting a file upload size limitation. Files that exceed the size limitation are rejected by the server. By default the setting is not configured on the server. It is only required if digital certificates are enabled on the web server. Running an IIS script from DOS is required to update this setting.

Client cannot renegotiate request and returns an HTTP 413 error (IIS 6.0):

http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/7e0d74d3-ca01-4d36-8ac7-6b2ca03fd383.mspx

UploadReadAheadSize Metabase Property (IIS 6.0):

http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/48900606-4881-4a93-a4c1-0e0ac622fee6.mspx