Visual Studio 2012, IIS Express, and Fiddler

From the mail bag… Q:When I use IE10 on Windows 8 to visit an IIS Express instance using the following URL http://ipv4.fiddler:2468/, I get an unexpected error message. HTTP/1.1 400 Bad RequestContent-Type: text/html;charset=us-asciiServer: Microsoft-HTTPAPI/2.0Date: Wed, 22 Aug 2012 19:59:52 GMTConnection: closeContent-Length: 334 <!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01//EN””http://www.w3.org/TR/html4/strict.dtd”><HTML><HEAD><TITLE>Bad Request</TITLE><META HTTP-EQUIV=”Content-Type” Content=”text/html; charset=us-ascii”></HEAD><BODY><h2>Bad Request – Invalid Hostname</h2><hr><p>HTTP Error 400….


My book “Debugging with Fiddler”, is now available

I’m delighted to announce that my new full-length book on Fiddler is now available. Weighing in at 330 pages, it covers every feature in Fiddler, and provides the most comprehensive available documentation of how to develop Fiddler extensions (including Inspectors, Transcoders, and IFiddlerExtensions) and build on the FiddlerCore class library. The book is available in…


Sneak Peek at Table of Contents for the Upcoming Fiddler Book

Table of Contents Acknowledgements………………………………………………………………………………………………………………………………………… iii Table of Contents……………………………………………………………………………………………………………………………………………. iv Origins……………………………………………………………………………………………………………………………………………………………… 1 About this book…………………………………………………………………………………………………………………………………………… 3 A Quick Primer………………………………………………………………………………………………………………………………………………… 5 Basic Concepts…………………………………………………………………………………………………………………………………………….. 5 Fiddler Scenarios………………………………………………………………………………………………………………………………………… 6 Getting Started with Fiddler…………………………………………………………………………………………………………………………….. 8 System Requirements…………………………………………………………………………………………………………………………………. 8 Installing Fiddler………………………………………………………………………………………………………………………………………….. 8 Updating Fiddler………………………………………………………………………………………………………………………………………….. 9 The Fiddler User-Interface…………………………………………………………………………………………………………………………….. 10 The Web Sessions List……………………………………………………………………………………………………………………………….. 10 Web Sessions Context Menu…………………………………………………………………………………………………………………….. 13 Fiddler’s Main…


Cookie Scanning with Fiddler

With the recent kerfuffle about sites providing misleading P3P statements, I decided to throw together a quick Fiddler add-on that displays privacy information simply in the Fiddler UI. Install the new Privacy Scanner add-on and Fiddler will gain a new top-level menu named Privacy. The menu has two options. The Enabled option controls whether the…


ThinkPad Scrolling and Fiddler

I’m a long-time ThinkPad fan and owner—the keyboards are sublime, and I love the TrackPoint interface. What I don’t love is the ThinkPad driver software, which doesn’t send the standard WM_MOUSEWHEEL messages to the system. That bug means that many .NET controls don’t scroll properly. Over the years, I’ve fixed many of the controls in…


Revisiting Fiddler and Win8+ Immersive applications

Back in September, I blogged about the configuration steps required to debug Windows 8 Immersive (“Metro-style”) apps using Fiddler. Since that post was originally written, I’ve made available a new version of Fiddler which runs natively on the .NETv4 Framework, enabling Windows 8 users to run Fiddler without installing older versions of the Framework. As…


.NET HttpWebRequests and Expect: 100-continue

Recently, a colleague asked me to look at a network capture in which a .NET client application’s communication with a web service was not meeting their performance goals. In particular, he noted that this was primarily a problem on high-latency networks; each of the dozens of requests took hundreds of milliseconds, even when existing connections…


News on Fiddler Surveys and Telemetry

For this morning’s post, I wanted to give everyone a quick picture of some of the data I’ve collected about Fiddler usage, how I plan to respond, and how I will continue to learn more. I’ve recently had the chance to run some surveys and spend some time with developers who are using Fiddler, and…


Generating HTML5 AppCache Manifests with Fiddler

HTML5 introduces the concept of an Application Cache, which allows a web developer to provide a manifest of pages that should be cached to permit offline use. You can see an instance of AppCache over on the IETestDrive site; if you examine the markup, you can find that the HTML tag contains a manifest attribute…