Capturing Traffic of a program using Fiddler

Question

I tried to use a website's API, but I always become a ProtocolError (UnsafeHeaderParsing did not help me) so I decide to capture the traffic of a program which is using that API, so that I know which attributes I have to set in the Header/POST...The problem is that Fiddler is currently only capturing the traffic of my browsers, how can I change that so, that it captures traffic of programs which are runnung on my localhost.

You haven't told us anything about what program you're trying to capture. Fiddler can capture HTTP/HTTPS traffic from virtually everything. — EricLaw, Oct 13 '14 at 20:36

score 1 · Accepted Answer · edited May 23 '17 at 12:27

1

Message Analyzer can do a great deal of capture and analysis, correlating events and so on. You can download it here.

NetMon is the old alternative, now replaced by Message Analyzer.

An of course, Wireshark if you want a non-OS alternative.

Also read Wireshark vs Firebug vs Fiddler - pros and cons?

edited May 23 '17 at 12:27

Community

1
1

answered Oct 12 '14 at 13:57

Remus Rusanu

288,378
40
442
569

score 0 · Answer 2 · answered Oct 12 '14 at 14:10

Assuming you are using ASP.Net (either MVCor Webforms) you need to set a proxy in your web application.
In order to do that, you need to change your web.config and set the defaultProxy setting to the Fiddler proxy:

<configuration>
<system.net>
  <defaultProxy>
   <proxy bypassonlocal="false" usesystemdefault="true" />
  </defaultProxy>
</system.net>
</configuration>

After changing the web.config, you'll see the request/responses made by your application in Fiddler.

See ref: http://docs.telerik.com/fiddler/configure-fiddler/tasks/ConfigureDotNETApp

I want to capture the traffic of an extern program, not a program made by me. — Feve123, Oct 12 '14 at 14:23

Capturing Traffic of a program using Fiddler

2 Answers2