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really odd one here.

I have a website which runs on IIS fine most of the time. On some occasions though I get a white 404 page with the text:

Not Found HTTP Error 404. The requested resource is not found.

Running fiddler I can see the following http headers:

HTTP/1.1 404 Not Found Content-Type: text/html; charset=us-ascii Server: Microsoft-HTTPAPI/2.0 Date: Thu, 10 Nov 2011 21:25:01 GMT Connection: close Content-Length: 315

So a "connection close" error seems to be happening intermittently.

A couple of refreshes later the page loads fine with the following headers:

HTTP/1.1 200 OK Content-Type: text/html Last-Modified: Thu, 10 Nov 2011 15:53:56 GMT Accept-Ranges: bytes ETag: "02d1f3c09fcc1:0" Server: Microsoft-IIS/7.5 X-Powered-By: ASP.NET mycustomheader: 01 Date: Thu, 10 Nov 2011 21:25:24 GMT Content-Length: 16307

I notice that the 404 header doesn't have custom http header response which I've added as part of my debug steps. In IIS if an error is being served by a specific web should it not have the custom header aswell?

Anyone know why certain http requests would intermittently be closed by IIS?



share|improve this question
Did you ever get to the bottom of this? – Lloyd Jul 3 '12 at 9:34
Would be nice to know if you came across a solution. I have a similar problem. – stoj Feb 4 '13 at 18:00
what kind of content is this? – bkr May 30 '14 at 4:38
Wow. This is old, and you probably don't care anymore. Anyhow, the problem isn't that the connection is being closed; that's just a 404 error. From your response headers, it's obvious that your code isn't even being touched. The response is coming from the lower-level HTTP subsystem; IIS isn't even getting to the Asp.Net pipeline. For whatever the reason, it's not finding your .aspx file. I would suggest you look at the filesystem/OS level for answers. – Granger Jul 11 '14 at 15:48

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