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FTPWebRequest: Unable to connect to server

I've written a site in ASP.NET which uses FTPWebRequest to download a text file from an FTP server every 15 seconds. When I run it on my computer, it works just fine. When I upload it to our server, the FTP download fails. No exception, it just returns 0 values.
I thought there might be an issue with the firewall, so I disabled the Windows firewall, and disabled outgoing firewall, same problem. Tried both active and passive FTP. Is it possible I need to change some settings in IIS Manager?
Running IIS 10 on Server 2012 R2, on the same VM with Exchange 2016.
Part of the code:
public static string[] GetTXT()
{
// Get the object used to communicate with the server.
FtpWebRequest request = (FtpWebRequest)WebRequest.Create("FTP address");
request.Method = WebRequestMethods.Ftp.DownloadFile;
request.UsePassive = false; //tried it with true as well
request.Credentials = new NetworkCredential("user", "pass");
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
Stream responseStream = response.GetResponseStream();
StreamReader reader = new StreamReader(responseStream);
string result = (reader.ReadToEnd());
}

Eventually discovered I was publishing the site in a subfolder.
The root folder probably contained an older version.
Anyway, thanks for the help!

If just a download from the server FTP, I recommend this class WebClient implemented by Microsoft for your method.
It maybe resolves your problem.
public static string[] GetTXT()
{
using (WebClient client = new WebClient())
{
var path = #"C:\local\path\file.txt";
client.Credentials = new NetworkCredential("log", "pass");
client.DownloadFile("ftp://ftp.example.com/remote/path/file.txt", path);
}
if (File.Exists(path))
{
return File.ReadAllLines(path);
}
//return something
}

C# HTTP request with proxy [duplicate]

I am using a web client class in my source code for downloading a string using http.
This was working fine. However, the clients in the company are all connected now to a proxy server. And the problem started from this.
When I have tested my application I don't think it can pass through the proxy server, as the exception that keeps getting thrown is "no response from xxx.xxx.xxx.xxx which is the proxy server IP address.
However, I can still navigate to the web site URL and it displays the string correctly in the browser when connecting through a proxy server, but not when I use my web client.
Is there something in the web client that I have to configure to allow me to access the url from behind a proxy server?
using (WebClient wc = new WebClient())
{
string strURL = "http://xxxxxxxxxxxxxxxxxxxxxxxx";
//Download only when the webclient is not busy.
if (!wc.IsBusy)
{
string rtn_msg = string.Empty;
try
{
rtn_msg = wc.DownloadString(new Uri(strURL));
return rtn_msg;
}
catch (WebException ex)
{
Console.Write(ex.Message);
return false;
}
catch (Exception ex)
{
Console.Write(ex.Message);
return false;
}
}
else
{
System.Windows.Forms.MessageBox.Show("Busy please try again");
return false;
}
}

My solution:
WebClient client = new WebClient();
WebProxy wp = new WebProxy(" proxy server url here");
client.Proxy = wp;
string str = client.DownloadString("http://www.google.com");

If you need to authenticate to the proxy, you need to set UseDefaultCredentials to false, and set the proxy Credentials.
WebProxy proxy = new WebProxy();
proxy.Address = new Uri("mywebproxyserver.com");
proxy.Credentials = new NetworkCredential("usernameHere", "pa****rdHere"); //These can be replaced by user input
proxy.UseDefaultCredentials = false;
proxy.BypassProxyOnLocal = false; //still use the proxy for local addresses
WebClient client = new WebClient();
client.Proxy = proxy;
string doc = client.DownloadString("http://www.google.com/");
If all you need is a simple proxy, you skip most of the lines above though. All you need is:
WebProxy proxy = new WebProxy("mywebproxyserver.com");

The answer proposed by Jonathan is proper, but requires that you specify the proxy credentials and url in the code. Usually, it is better to allow usage of the credentials as setup in the system by default (Users typically configure LAN Settings anyway in case they use a proxy)...
The below answer has been provided by Davide in earlier answer, but that requires modifying the app.config files. This solution is probably more useful since it does the same thing IN CODE.
In order to let the application use the default proxy settings as used in the user's system, one can use the following code:
IWebProxy wp = WebRequest.DefaultWebProxy;
wp.Credentials = CredentialCache.DefaultCredentials;
wc.Proxy = wp;
This will allow the application code to use the proxy (with logged-in credentials and default proxy url settings)... No headaches! :)
Hope this helps future viewers of this page to solve their problem!

I've encountered the same issue but using a webclient for downloading a file from the internet with a Winform application the solution was adding in the app.config:
<system.net>
<defaultProxy useDefaultCredentials="true" />
</system.net>
The same solution will work for an asp.net app inserting the same rows in web.config.
Hope it will help.

You need to configure the proxy in the WebClient object.
See the WebClient.Proxy property:
http://msdn.microsoft.com/en-us/library/system.net.webclient.proxy(VS.80).aspx

byte[] data;
using (WebClient client = new WebClient())
{
ICredentials cred;
cred = new NetworkCredential("xmen#test.com", "mybestpassword");
client.Proxy = new WebProxy("192.168.0.1",8000);
client.Credentials = cred;
string myurl="http://mytestsite.com/source.jpg";
data = client.DownloadData(myUrl);
}
File.WriteAllBytes(#"c:\images\target.jpg", data);

All previous answers have some merit, but the actual answer only needs ONE line:
wc.Proxy = new WebProxy("127.0.0.1", 8888);
where wc is the WebClient object, and 8888 is the port number of the proxy server located on the same machine.

Accessing HTTPS URL With Credentials

I have a HTTPS URL which i am trying to connect to but not able to and keep getting 401 unauthorized.
I tried to access the same URL over Web Browser (both at home and in company) and was able to connect to it. After i execute the HTTPS URL (which has some parameters in it like date etc) in the browser, it prompts for username and pwd and when i enter it, it gives the xml back in response.
I tried following segment of code on my home PC and it worked fine but when i tried same in office network, it gave me 407 error. I thereafter embedded the proxy code in it and now i don't get 407 rather i keep getting 401. Please help
Working Code on Home:
public static void WorkingCode()
{
string URL = "https://webservice.XYZ.com/display/?start_date=2015-05-06&end_date=2015-05-07";
Uri uri = new Uri(URL);
WebClient wc = new WebClient();
wc.Credentials = new NetworkCredential("username123", "Password123");
string results;
results = wc.DownloadString(uri);
Console.Write(results);
Console.Read();
}
Code within Organization with PROXY:
public static void WorkingCode()
{
string URL = "https://webservice.XYZ.com/display/?start_date=2015-05-06&end_date=2015-05-07";
Uri uri = new Uri(URL);
WebClient wc = new WebClient();
wc.Credentials = new NetworkCredential("username123", "Password123");
string results;
/* PROXY CODE*/
WebProxy myProxy = new WebProxy("frproxyseczom.PPP.com", 8080);
myProxy.UseDefaultCredentials = true;
wc.Proxy = myProxy;
/*---------------*/
results = wc.DownloadString(uri);
Console.Write(results);
Console.Read();
}
Because of security reasons, i have modified some details such as URL's, username and pwd.

You're probably getting a 401 in the proxy code because you're missing "http://" in the web proxy address.

Using Proxy Automatic Configuration from IE Settings in .Net

I'm having trouble getting Proxy Automatic Configuration (PAC) in IE options to work as expected using .Net WebRequest.
According to this article:
Proxy Detection
Take the Burden Off Users with Automatic Configuration in .NET
The system proxy should be set by default with to each WebRequest.
That's how the proxy.js pac file looks like:
function FindProxyForURL(url, host)
{
return "PROXY ProxyServerName:3118; DIRECT;";
}
I also took a look at this post: How should I set the default proxy to use default credentials?
Which suggests to add this in the app.config:
<system.net>
<defaultProxy useDefaultCredentials="true" />
</system.net>
Adding this did not help.
I created a small console application just to test this out.. here it is:
static void Main(string[] args)
{
HttpWebRequest request = null;
try
{
String resolvedAddress = WebRequest.DefaultWebProxy.GetProxy(new Uri("http://www.google.com")).ToString();
Console.WriteLine("Proxy for address is: " + resolvedAddress);
Uri m_URLToTest = new Uri("http://www.google.com");
request = WebRequest.Create(m_URLToTest) as HttpWebRequest;
request.Method = "GET";
request.KeepAlive = false;
request.Timeout = 5000;
request.Proxy = WebRequest.DefaultWebProxy;
WebResponse response = request.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string message = reader.ReadToEnd();
}
catch (Exception ex)
{
Console.Write("Exception");
}
}
The output:
Proxy for address is http://www.google.com
instead of Proxy for address is ProxyServerName:3118
It happens only when using auto configuration script...
Did I miss anything? Please help!

Found the solution!
It is really important that the mime type of the PAC file would be: [Content-type: application/x-ns-proxy-autoconfig]
Other mime types might not work.
Make sure using fiddler2 (with cache disabled) that the mime type is appropriate.
Some configurations might show Content-Type: text/plain which is bad.

Make sure you have checked Internet (Client & Server) and Private Networks (Client & Server) capabilities in Package.appxmanifest.
[Source]

Proxy Basic Authentication in C#: HTTP 407 error

I am working with a proxy that requires authentication, i.e., in a browser if I try to open a page it will immediately ask for credentials. I supplied same credentials in my program but it fails with HTTP 407 error.
Here is my code:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
IWebProxy proxy = WebRequest.GetSystemWebProxy();
CredentialCache cc = new CredentialCache();
NetworkCredential nc = new NetworkCredential();
nc.UserName = "userName";
nc.Password = "password";
nc.Domain = "mydomain";
cc.Add("http://20.154.23.100", 8888, "Basic", nc);
proxy.Credentials = cc;
//proxy.Credentials = System.Net.CredentialCache.DefaultCredentials;
request.Proxy = proxy;
request.Proxy.Credentials = cc;
request.Credentials = cc;
request.PreAuthenticate = true;
I have tried every possible thing but seem like I am missing something.
Is it something like, I have to make two requests? First with out credentials and once I hear back from server about need for credentials, make same request with credentials?

This method may avoid the need to hard code or configure proxy credentials, which may be desirable.
Put this in your application configuration file - probably app.config. Visual Studio will rename it to yourappname.exe.config on build, and it will end up next to your executable. If you don't have an application configuration file, just add one using Add New Item in Visual Studio.
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.net>
<defaultProxy useDefaultCredentials="true" />
</system.net>
</configuration>

I was getting a very similar situation where the HttpWebRequest wasn't picking up the correct proxy details by default and setting the UseDefaultCredentials didn't work either. Forcing the settings in code however worked a treat:
IWebProxy proxy = myWebRequest.Proxy;
if (proxy != null) {
string proxyuri = proxy.GetProxy(myWebRequest.RequestUri).ToString();
myWebRequest.UseDefaultCredentials = true;
myWebRequest.Proxy = new WebProxy(proxyuri, false);
myWebRequest.Proxy.Credentials = System.Net.CredentialCache.DefaultCredentials;
}
and because this uses the default credentials it should not ask the user for their details.

here is the correct way of using proxy along with creds..
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
IWebProxy proxy = request.Proxy;
if (proxy != null)
{
Console.WriteLine("Proxy: {0}", proxy.GetProxy(request.RequestUri));
}
else
{
Console.WriteLine("Proxy is null; no proxy will be used");
}
WebProxy myProxy = new WebProxy();
Uri newUri = new Uri("http://20.154.23.100:8888");
// Associate the newUri object to 'myProxy' object so that new myProxy settings can be set.
myProxy.Address = newUri;
// Create a NetworkCredential object and associate it with the
// Proxy property of request object.
myProxy.Credentials = new NetworkCredential("userName", "password");
request.Proxy = myProxy;
Thanks everyone for help... :)

This problem had been bugging me for years the only workaround for me was to ask our networks team to make exceptions on our firewall so that certain URL requests didn't need to be authenticated on the proxy which is not ideal.
Recently I upgraded the project to .NET 4 from 3.5 and the code just started working using the default credentials for the proxy, no hardcoding of credentials etc.
request.Proxy.Credentials = CredentialCache.DefaultCredentials;

I had a similar problem due to a password protected proxy server and couldn't find much in the way of information out there - hopefully this helps someone. I wanted to pick up the credentials as used by the customer's browser. However, the CredentialCache.DefaultCredentials and DefaultNetworkCredentials aren't working when the proxy has it's own username and password even though I had entered these details to ensure thatInternet explorer and Edge had access.
The solution for me in the end was to use a nuget package called "CredentialManagement.Standard" and the below code:
using WebClient webClient = new WebClient();
var request = WebRequest.Create("http://google.co.uk");
var proxy = request.Proxy.GetProxy(new Uri("http://google.co.uk"));
var cmgr = new CredentialManagement.Credential() { Target = proxy.Host };
if (cmgr.Load())
{
var credentials = new NetworkCredential(cmgr.Username, cmgr.Password);
webClient.Proxy.Credentials = credentials;
webClient.Credentials = credentials;
}
This grabs credentials from 'Credentials Manager' - which can be found via Windows - click Start then search for 'Credentials Manager'. Credentials for the proxy that were manually entered when prompted by the browser will be in the Windows Credentials section.

You can use like this, it works!
WebProxy proxy = new WebProxy
{
Address = new Uri(""),
Credentials = new NetworkCredential("", "")
};
HttpClientHandler httpClientHandler = new HttpClientHandler
{
Proxy = proxy,
UseProxy = true
};
HttpClient client = new HttpClient(httpClientHandler);
HttpResponseMessage response = await client.PostAsync("...");

try this
var YourURL = "http://yourUrl/";
HttpClientHandler handler = new HttpClientHandler()
{
Proxy = new WebProxy("http://127.0.0.1:8888"),
UseProxy = true,
};
Console.WriteLine(YourURL);
HttpClient client = new HttpClient(handler);