How can i debug HTTP sessions using Fiddler, just like i did with TcpTrace?

Question

Im trying to stop using TcpTrace and start working with Fiddler.

But i just can't setup fiddler to just start listening specified port and redirect all requests to the specified WS with another port.

All i want is just redirect and monitor all traffic from localhost:4747 -> webservice-ip:10000
Is there any solution for my problem ?

Thanks in advance.

You have to set your web client to honor the Internet Explorer proxy settings *or* manually configure it to use Fiddler as a proxy. — bzlm, Sep 20 '10 at 08:33
I dont need a web client. I have a local webserver that sends all HTTP requests to the localhost:4747. I want to redirect traffic from 4747 to external:1000 — Igor Konoplyanko, Sep 20 '10 at 08:41

score 2 · Accepted Answer · answered Sep 20 '10 at 08:48

2

Set Fiddler to listen on port 4747, and then edit your CustomRules.js (menu->Rules->Customize Rules). Putting something like this into the OnBeforeRequest method should help:

if (oSession.host=="localhost:4747") {
  oSession.host="external:1000";
}

if you want all traffic passing through Fiddler to go to the external host, you can simply use

oSession.host="external:1000";

(where external is the hostname of the external host)

answered Sep 20 '10 at 08:48

Piskvor left the building

91,498
46
177
222

See also http://www.fiddler2.com/fiddler/dev/scriptsamples.asp for other useful snippets you can use in your CustomRules. – Piskvor left the building Sep 20 '10 at 08:51
@Konoplianko: You're welcome. Had a similar problem some time ago :) (Fiddler ROCKS!) – Piskvor left the building Sep 20 '10 at 09:12
I have another problem. now fiddler responses with its own content. – Igor Konoplyanko Sep 20 '10 at 09:25
i wrote in the script: oSession.host="10.233.103.53:10000"; but that means it doesnt works then. – Igor Konoplyanko Sep 20 '10 at 09:29
yes. directly it works good. seems that this script doesn't work. – Igor Konoplyanko Sep 20 '10 at 10:16
2

The redirection script above would only happen if you typed "localhost:4747" into your browser. And that would never work in most browsers because they bypass the proxy for the "localhost" name. You should probably change your "if" condition such that it checks ONLY the port and not the hostname and port. – EricLaw Sep 26 '10 at 21:16

How can i debug HTTP sessions using Fiddler, just like i did with TcpTrace?

1 Answers1