I'm not a network expert, but for one of my projects, I need to ensure that the website I'm sending the request to is alive. Some websites do not respond to ping; basically, their configuration prevents response to ping requests.
I was trying to Arping instead of pinging websites, but Arping only works on the local network and will not go beyond the network segment (this).
I can download the whole or part of the webpage and confirm if the content is the same as the previous state, but I rather have one more level of confirmation before downloading Html.
Is there any other method that enables the app to get a response back from non-pingable websites outside the network?
Based on common practices you may use ping, telnet and tracert as a client to the requested server (at this point the website or the service you want to connect) and make sure the 3 command are enable to your side. You may also try to access it to your browser.
If its API you may also try to use POSTMAN and call the service.
Goodluck and happy coding :)
Related
I have a project and it contains 2 pages: test1.aspx and test2.aspx. Now from test1.aspx I want to manually request test2.aspx and get the HTML out of it. I could do this using HttpClient or HttpWebRequest. Problem is I have a firewall and I suspect it won't work. Is there any other way to download the content from the webpage without actually using HttpWebRequest
Thanks in advance.
I don't really like what you are trying to do ;) Anyway, since your page don't seems to be a static page (.aspx) you must do a request to your webserver, whatever the method you use (HttpClient or HttpWebRequest).
Usually, a request done on the same machine does not passes through the network. If the DNS alias point to the machine IP address a loopback occurs.
In this case:
if your firewall is somewhere on your network, you don't care about
it, the request will not leave your host
if you speak about a firewall software, on your machine, it may block
the request. You may have to authorize such requests or force the DNS locally in your host file to specify 127.0.0.1 (which is a true localhost) and may work with
most firewall software
if you are on a Windows Server and your site require authentication, you may have to deal with Loopback
Check (or here)
NB: Loopbacks are usually considered as security breach and not recommended.
You should think about another solution like Ajax Web Services, Web or User controls (as already said) etc...
I want to write a little c# tool for a web application (which runs inside a browser). Unfortunately, I have no idea how to hang into the HTTP communication.
There are a lot of tools that listen to network traffic and extracting relevant data out of it so I guess there must be a solution. My current approach is to catch the responses by listening on the corresponding port. But:
HTTPListener seems to be a server-side class that accepts HTTP requests
HTTPRequest is just the message object and has to be received before
I don't think TCPListener would be applicable because I don't want to create a connection
Is there another solution how to just get the server response without sending a request? Or might another approach be more reasonable?
I don't want to write a proxy because I simply don't want a server, just a lightweight, easy-to-use tool.
I was not able to find any hints on this topic since all results of my searches were about receiving responses to own requests or similar.
Thanks in advance for any solutions or suggestions!
Phil
If you don't got the idea of the tool, here is an example:
A user has firefox running and navigates to the target web application
He does anything and the web application sends the corresponding data to the web server
The web server processes the request and sends back a response
The web application updates itself inside the browser to display the received data
My tool (C# application) should do the following:
Catch the response of step 3 and evaluate the response to also update its own state
OR: do anything else (suggestions?) to keep its state up-to-date
I wanted to know what is the best way to write an agent on Win platform that will be able to monitor browser's communication.
scenario: monitor the user access to predefined url on Chrome, FireFox and IE. On each hit I send the stats to a server with some data (page title).
The ways I found so far are proxy and browser addons. Each has it's own advantages and disadvantages. The main disadvantage of the proxy way is handling of HTTPS communication. The addon disadvantage is the installation (need to install on every browser) and cross-browser support.
Is there another way? some service I can write with .net that will automatically hook on a browser when it is started?
Thanks you.
You do have only two choices - an http proxy, or to write a plugin for every browser. That plugin could just forward data via network to a central service, leaving you with the challenge of coming up with a common set of data that all browsers can provide, plus learning all the plugin models.
In my opinion, though, the only real option is an HTTP(s) proxy because otherwise you have to keep updating your plugins every time browsers change, or deal with the fact that new browsers can come along and be used.
Certainly you won't find a 'user is browsing a url in some browser' event in the OS - all it knows is that a socket connection has been opened on some local port to a remote server's port 80/443 (or whatever).
So I strongly suggest building on top of the excellent work that's behind Fiddler and use the Fiddler Core.
http://www.telerik.com/fiddler/fiddlercore
For https you have to decrypt and re-encrypt with a different certificate. The information that you need is just not available without actually unpacking the request. Fiddler achieves this by opening it's own SSL tunnel to the target server on the client's behalf, whilst acting as an SSL server to the client under a different certificate. So long as the certificate that it uses is fully trusted by the client, no problems occur.
That said, it means that the user cannot personally verify the identify of the target site - therefore your system would have to assume worst case scenario for any invalid SSL certificates and block the connection.
I'm working on a project that has a C# app (running 24/7 as a server) on the client's machine). This app needs to send a file as a byte stream via POST to a server I am currently hosting on my home desktop.
Can this file be received by a C# app running on my server, or does it have to be as ASP app/page?
Also, I know how to send a bytestream via POST, but how will I set my server side app to listen for this incoming data?
I have never done something like this, so I'm looking for some pointers to get me started.
Thanks
Depending on what you need to do with the file, and when it's uploaded, there is nothing wrong with using a tiny asp.net app to do this.
If the only way you can get the file to the server is via http POST, why write your own service/daemon to run a listener? Unless you have some reason not to run it in IIS, I would do it there. There is the full stack available that way for authentication and so on if you should happen to need it. Besides, if you have to upload files via http post, I would bet you will end up wanting other methods available via HTTP as well..
You're looking for this guy:
http://msdn.microsoft.com/en-us/library/system.net.httplistener.aspx
Using that, you'll create basically a mini HTTP server, listening on some port you specify. You'll then be able to post data to it, and process it accordingly (similar to if the processing code was in an ASPX code-behind).
Assuming your open to sending directly via TCP you can look at this example if you dont wanna go the HTTP way. I personaly like the NetworkStream Class, for sending data over the network painfree.
I have a standard web server that serve web pages.
I want to monitor traffic on port 80, intercept every http responses, and add/inject an additionnal header to them.
The process will then act like a proxy between the web server and the client.
Could you please give me some pointers? I'm already aware of SharpPCap, but I'm not sure where to start.
Note: I can't rely on the web server, I can't control it or change it's configuration. However I can install any other process on the same machine.
Thanks a million
I think that SharpPCap is an overkill here.
Try:
listen on a port (say 8080)
for each incoming connection, accept and open one to the server (original one, port 80)
pass everything that comes in from the client straight to the server
pass everything that comes from the server back to the client, monitoring the stream and injecting/modifying if needed
I think what you want to do can be done with IIS 7.0 URL Rewrite module instead of rolling your own code.
http://learn.iis.net/page.aspx/711/modifying-http-response-headers/