asp.netvisual-studiolocalhostfiddlerweb-traffic

Reputation: 25260

How to display localhost traffic in Fiddler while debugging an ASP.NET application?

How do I display localhost traffic in Fiddler while debugging an ASP.NET application?

Upvotes: 80

Answers (14)

Legends

Reputation: 22672

Using Fiddler v4:

Check your IE proxy settings

IE->Tools->Internet Options->Connections->Lan Settings

Check your settings in Fiddler:

Fiddler -> Options-> Connections & Https

Check the Fiddler port, default is 8888

In Fiddler-Menu:

File -> Capture Traffic is checked

The following solution worked for me, when using a

HttpClient or
WebClient from inside an ASP.NET application.

Web.config

<system.net>
    <defaultProxy
                enabled = "true"
                useDefaultCredentials = "true">
      <proxy autoDetect="False" bypassonlocal="False" proxyaddress="http://127.0.0.1:8888" usesystemdefault="False" />
    </defaultProxy>

Code:

var resourceServerUri = new Uri("http://localhost.fiddler:YourAppServicePort");
var body = c.GetStringAsync(new Uri(resourceServerUri)).Result;

Check if your request actually reaches fiddler by customizing the Fiddler Rules script

Fiddler->Rules->Customize Rules

and hook into the OnBeforeRequest event:

static function OnBeforeRequest(oSession: Session) {

if (oSession.hostname.Contains("localhost:YourPortNumber")
{
 System.Windows.Forms.MessageBox.Show(oSession.hostname);  
}

Or explicitly by setting a web proxy

WebClient wc = new WebClient();

WebProxy proxy = new WebProxy();
// try one of these URIs
proxy.Address = new Uri("http://127.0.0.1:8888");
proxy.Address = new Uri("http://hostname:8888");
proxy.Address = new Uri("http://localhost.fiddler");
proxy.Address = new Uri("http://ipv4.fiddler");
// https://en.wikipedia.org/wiki/IPv6
proxy.Address = new Uri("http://ipv6.fiddler");

proxy.BypassProxyOnLocal = false; wc.Proxy = proxy;
var b = wc.DownloadString(new Uri(YourResourceServerBaseAddress));

Upvotes: 4

bendewey

Reputation: 40235

try using this:

http://ipv4.fiddler/folder

instead of

http://localhost/folder

this also works with ports

http://ipv4.fiddler:12345/folder

Here is link to fiddler documentation

http://docs.telerik.com/fiddler/Configure-Fiddler/Tasks/MonitorLocalTraffic

Upvotes: 88

charlie.mott

Reputation: 361

If trying to catpure HTTPS traffic on a local machine from BizTalk using Fiddler, try using the WCF Adapter Proxy settings. I used an address of: http://localhost:8888/

Upvotes: 1

user1932039

Reputation: 21

One of the possible solutions is remove the proxy settings in IE as follows.

       IE->Tools->Internet Options->Connections->Lan Settings->

disable following

Automatically detect settings
Use automatic configuration script

Upvotes: 2

mdonatas

Reputation: 1768

To make Fiddler work on localhost with IIS Express you should use this form of URL

http://localhost.fiddler:50262/

This puts correct Host header value (localhost) which satisfies IIS Express.

Upvotes: 52

David Norris-Hill

Reputation: 301

Checking the "Use PAC Script" in Fiddler Options -> Connections worked for me when using IIS Express within a corporate intranet.

Upvotes: 3

long

Reputation: 414

You may use PC hostname instead of 127.0.0.1 or localhost

Upvotes: 3

akjal

Reputation: 201

Start Fiddler. Go to Tools--> Fiddler Options. Choose Connections tab. Check the 'USe PAC Script' option.

Now you will be able to monitor local traffic as well

Upvotes: 20

nikib3ro

Reputation: 20596

Try with http://127.0.0.1. <-- note the . at the end

So you can still connect to Casini and debug easily (I'm currently debugging page on http://127.0.0.1.:1718/login/Default.aspx ).

Upvotes: 2

M4N

Reputation: 96561

Probably the easiest way to monitor traffic to localhost is to replace "localhost" with "localhost." in the browser's URL bar. E.g.

http://localhost./MyApp/default.aspx

Upvotes: 7

Michael Kniskern

Reputation: 25260

For an ASP.NET web site project:

1) Right-click the project and select Property Pages
2) Select Start Options
3) Under the Server section, click the "Use custom server" and edit the Base URL by replacing localhost with your computer's name.

Upvotes: 12