Random sessions using Fiddler - fiddler

all,
I use Fiddler for developing and debugging Web apps, and I find that random stuff shows up in the list of "sessions" after I turn off Capture Traffic. It's perhaps a few items every ten or fifteen minutes. I know this is a really broad question, but is there some way to figure out why these things are showing up and what they are?
Thanks!

The Capture Traffic setting controls whether or not Fiddler is registered as the system's proxy server. Most clients (Internet Explorer, etc) will react to the system proxy setting at runtime, so that when you disable the Capture traffic setting, they'll stop sending traffic to Fiddler.
However, some clients (particularly .NET applications) do not react to proxy setting changes and always use whatever proxy was set when the client was started; they'll continue to send traffic to Fiddler until the client is restarted.
You can examine the Process column in Fiddler to see what client isn't properly reacting to changes in the system's proxy setting.

You likely have web pages open that periodically hit the server from within javascript (ajax calls), fiddler captures that traffic and that's what you're seeing.

Related

Raspberry Pi and Windows IoT

I am working on an automation project using Raspberry pi and Windows IoT. Is it possible to broadcast to a web page, similar to Server-Send-Event? I am monitoring certain events and instead of calling server every few seconds for updates, I would like server to send the alert to web page direct. Any help would be greatly appreciated.
I think you can use WebSockets. WebSockets are an advanced technology that makes it possible to open an interactive communication session between the user's browser and a server. You can refer to this sample. Or you can use IoTWeb to embed a simple HTTP and WebSocket server into your application.
Update:
WebSockets are a great addition to the HTTP protocol suite, but there are numerous situations where they cannot be used.
Some companies have firewalls that will prevent WebSockets from
working.
If you are deploying software in a shared hosting
environment, you may not be permitted to use WebSockets.
If you are
behind a reverse proxy that isn’t configured or the software doesn’t
support pass-through of WebSocket protocol, WebSockets won’t work.
Another option is long polling,the browser does an XHR request and the server simply doesn’t respond until it has something to send. But in this way, if you want to do 2-way communications with the server, you are effectively using 2 sockets. One is tied up hanging/waiting for the long poll response, and the other is sent by the client to send new information to the server. Long polling is also problematic because the client has to be able to handle XHR errors, some of which are tricky to handle or even impossible to handle. You can search more differences and disadvantages from internet.

How to stop Fiddler 2 from logging requests made from web browsers and other applications?

I would like to use Fiddler 2 to make GET and POST requests and to analyze the responses, but it's made almost impossible because of how many other requests it logs from internet browsers and other applications.
How can I get Fiddler to only show requests that I made inside of it, along with the responses to those requests?
There are many ways to filter traffic by process in Fiddler; a simple search on any major search engine will turn up all of them.
For your needs, however, you simply don't want Fiddler to be the system proxy. Hit F12 or untick File > Capture Traffic; no other client will then send its traffic to Fiddler.
If you only ever care about requests from the Composer, click Tools > Fiddler Options and untick "Act as System Proxy on Startup" on the Connections tab.

Best way to view/monitor TCP/IP sockets from IE, Firefox, and/or Chrome?

I'm trying to write a sort-of web proxy but to make sure everything is working properly, I want to monitor an existing proxy server to see when the browser connects, disconnects, etc.
Are there any plugins for Firefox or Chrome (or Internet Explorer), to show me how many sockets it currently has open and what data was sent through them?
I know that I can use netstat to see a bit of information on socket state, but I'd really like to go a bit further and see what traffic was inside each socket specifically, etc.
Use a packet sniffer such as Wireshark, or a debugger such as Fiddler.
Use Microsoft Network Monitor. It's pretty easy to use. Once you capture packets, filter them just writing HTTP in the filter panel. In the left size, you will see a list of applications, choose Firefox, Chrome, IE or whatever you need, and it will display only packets sent and received by that application.

How to make fiddler less intrusive?

Fiddler is a great tool for testing a wide variety of http scenarios. However Fiddler also blocks all kinds of traffic that it shouldn't. This intrusive behavior can be annoying and time consuming.
Is there a way to specify what Fiddler does and does not listen to? So I want to say only monitor and report on traffic going to localhost or www.google.com, everything else would be ignored.
Is that possible ?
Its just rather tedious to have to close fiddler whenever it blocks something it should not.
Fiddler acts as a system proxy, so you can't have some traffic flow through it and some not, unless you can configure the client to not use the proxy for some connections.
You can use Fiddler's filter options to determine what is captured and shown in the sessions window.
However, what does it block ? I use Fiddler extensively, and have no issues with connections being blocked. Perhaps there is another solution than closing Fiddler.
I faced the same problem when setting up Fiddler just now (Win7). My problem was that Fiddler (Fiddler2) was not detecting and using my corporate Proxy settings. I had to go and set them manually in Fiddler Options > Gateway
That is why all my non-local, non-intranet traffic was appearing to blackhole. Hope that helps.

Detecting Port Utilized by Webbrowser

When the webbrowser control issues an HTTP request to a URL, it is assigned a port - which is utilized for the length of that connection.
Is there away to find out which port is being utilized for each connection the webbrowser control establishes/issues?
Every request is potentially using a different port. Since most requests are resolved in a couple of seconds and then closed, having the port information on the client isn't going to be very helpful.
If you're interested from a historical perspective, you can add the port number to the logs that many web servers generate.
In order to view this information live you can use a tool such as TCPView
Now for the real question. What are you trying to do? There may be an easier way.
you can run in background:
netstat -bn
and parse output to get information about your application (ports, ips, etc.)