We have a .NET Core 2.1 web application which is just run from the command line. E.g.

dotnet MyApp.dll --server.urls http://localhost:44321

The application communicates with other web services on localhost.

Fiddler tracing worked fine on our development machines, with all the traffic to the web services traced OK.

However, on the target machine, Fiddler did not tracing the web service traffic. It traced everything else. For example, traffic to/from our application, traffic to/from browsers.

The machine had .NET Core 2.1 installed with the "Runtime and hosting bundle" installer: https://dotnet.microsoft.com/download/dotnet-core/2.1

After trying various things (checking firewall, proxy, etc), we found the resolution was to install the SDK for .NET Core 2.1.

Does this imply that if we want to use Fiddler with .NET Core applications, we need to always have the SDK variant installed?

 

 

 

Hi Eric,

I am trying to capture the traffic of a mobile banking application installed in an Android device using Fiddler

Exactly followed the instructions on http://docs.telerik.com/fiddler/Configure-Fiddler/Tasks/ConfigureForAndroid , 
but I do not to see any HTTPS  calls after capturing the traffic ; I can only see the HTTP calls captured.


1) Even after installing "Fiddler Root Certificate" on device Trusted Credentials, why HTTPS calls did get captured ?

2) Do I need to speak with Dev. for a work around ? If so , can you please guide me what exactly has to done by Dev. at server/application level ?


Got stuck with these issues for long time.Appreciate your help please.

Regards
Lenin

I'm being using Fiddler for a while like a proxy on my old machine with Windows XP but, today upgrade the old version installed 5.0.20182.28034 to 5.0.20192.25091 and now the program doesn't work.

I cannot reinstall the old version because it installs the last one. See the attached image for technical info.

Any Solution?

Hey, guys. Please, help me.

 

How I can get readable body from websocket?

 

 

I want to read certain websocket traffic, but when using the combination of Fiddler & Chrome it is not read-able.

Inside Chrome developer tools they appear fine.  And if I use Microsoft Edge, it appears fine in Fiddler as well.

But when I use Chrome with Fiddler, it seems like there may be an extra layer of encryption or something that Fiddler doesn't handle?

Is there some setting or anything else I can tweak to make this combination work?

Attached is the view of Ping-Pong traffic as seen in Fiddler, but it isn't able to recognize these.

I have a web application which is specifically configured to use Fiddler as it's proxy in Web.Config independently of the setting of the system proxy. I am only interested in the traffic from/to this application so would prefer not to have the system proxy changed.

If I uncheck the option "Act as system proxy on startup", Fiddler starts, but isn't capturing. If I start capturing, it changes the system proxy.

If I change the system proxy using Settings, Fiddler pops up a yellow bar saying "The system proxy was changed. Click to reenable captuing". If I click, it starts capturing, but changes the system proxy again.

How do I tell Fiddler to start capturing but not to change the system proxy, i.e to only capture traffic from applications which specifically use it as a proxy?

I've change my Text Editing tool to VSCode, which works, except that the output file from "View in Notepad" is always named Rawfile.htm and if the file is already open in VSCode it doesn't seem to get updated.

If there a way to generated a custom name for each file being copied to a "Text Editor"?

If you look below the overall elapsed time given by fiddler is 1.377 seconds but when calculate the time between 11:56:17.495 & 11:56:20.382 it looks like it took 0:00:02.887 So how is the overall elapsed item calculated.

ClientConnected:11:56:17.495
ClientBeginRequest:11:56:19.004
GotRequestHeaders:11:56:19.004
ClientDoneRequest:11:56:19.004
Determine Gateway:0ms
DNS Lookup: 0ms
TCP/IP Connect:0ms
HTTPS Handshake:0ms
ServerConnected:11:56:17.744
FiddlerBeginRequest:11:56:19.004
ServerGotRequest:11:56:19.005
ServerBeginResponse:11:56:20.382
GotResponseHeaders:11:56:20.382
ServerDoneResponse:11:56:20.382
ClientBeginResponse:11:56:20.382
ClientDoneResponse:11:56:20.382

Overall Elapsed:0:00:01.377

 

 

 

Hi All,

 

I'm trying to solve an issue I've been facing for almost 2 weeks, trying to invoke a web service, using POST over HTTPS, which is getting the message "The underlying connection was closed". The strange thing is that the invoke works well when Fiddler is running on my PC.

 

I've read several post and forums entries, like the one wrote by Eric: http://blogs.telerik.com/fiddler/posts/13-02-28/help!-running-fiddler-fixes-my-app-. But none of the suggestions there worked for me. The server certificate seems to be trusted by my PC, so I think it's not related to that. 

 

So is there any way I can see what Fiddler does to change the original request?

 

The C# code I'm using is as follows, when I'm trying to reach the following web service: https://serviciospublicos.bse.com.uy/SeguridadServiciosWS/WsSeguridadServicios/

 

 ServicePointManager.Expect100Continue = true;
 ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
 ServicePointManager.SetTcpKeepAlive(true, 10000, 10000);
 ServicePointManager.DefaultConnectionLimit = 1000;
            
 WsSecureSvc.WsSecureClient client = new WsSecureSvc.WsSecureClient();
 WsSecureSvc.resultLog resp = client.log(someParam);

 

Please let me know if I'm doing something wrong there.

Any help would be really appreciatted as I'm totally stuck on getting this working.

Thanks!

Has the issue connecting the Google Pixel 3 to Fiddler been resolved? I cannot seem to capture mobile traffic from my Pixel 3 in Fiddler. Thank you!