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WinSCP .NET library FTP transfer fails with "IP addresses of control and data connection do not match"

I have implemented FTP code with use of WinSCP .NET assembly and hosted it on an Azure AppService.
It works locally and on Azure.
But in very few random times, when hosted on Azure, it throws the following error:
Error transferring file 'D:\local\Temp\test_settings.txt'. Server sent passive reply with unroutable address 10.YYY.YYY.YYY, using host address instead. Copying files to remote side failed. Rejected data connection for transfer of "/test_settings.txt", IP addresses of control and data connection do not match
Since the IP starts with 10. does that mean that it's local in the FTP server's network?
Can I do something to improve the implementation?
Do you think that the solution will have a problem when used concurrently by multiple requests?
My code is a copy of the Simple C# example with the following settings:
SessionOptions sessionOptions = new SessionOptions
{
Protocol = Protocol.Ftp,
UserName = username,
Password = password,
GiveUpSecurityAndAcceptAnyTlsHostCertificate = true,
FtpSecure = FtpSecure.Explicit,
HostName = 'ftp.domain.com'
};

IP addresses of control and data connection do not match
That's a message from FileZilla FTP server. It's a security measure. It might indicate that external IP address of your app service instance changed mid transfer. Or of course, it might indicate that you connection was hijacked (that's what the server tries to detect).
It has nothing to do with WinSCP.
I do not know if the IP address of the Azure app service can be fixed somehow. If not, all you can do is to reconnect and retry the transfer. I believe you would have the same problem with any FTP client. Maybe with IPv6 connection, the problem would not happen. But I'm not sure, it's just a wild guess. Though you cannot force IPv6 with WinSCP (only by disabling IPv4 altogether, but I do not know if that's even possible with the app service).

'No connection could be made because the target machine actively refused it'

I am working on a 'Smart Device Project' using .Net Framework 3.5. I am trying to connect to some Java SOAP services on a remote server.
In order to do that, I added 'Web References' to my project.
When I try to call my web service I get a WebException 'Unable to connect to the remote server' with the inner exception being 'No connection could be made because the target machine actively refused it'.
I searched quite a lot on the Web and StackOverflow and found a lot of ASP configuration and 'Unavaliable port' answers, but as I have another application using the exact same Service successfully, I can't get why the new one isn't getting through (It did sometimes through my tests so I suppose my client implementation isn't that bad)
I tried to look if there was some connection issue on the port by using some TcpClient:
System.Net.Sockets.TcpClient client = new System.Net.Sockets.TcpClient();
try
{
client.Connect("myServerName", 8087);
MessageBox.Show("Success");
} catch (Exception ex)
{
MessageBox.Show("Failure");
}
finally
{
client.Close();
}
This connection succeed.
Here is a sample on how I call my WebService:
WSServiceExtended srv = new WSServiceExtended();
srv.Proxy = new System.Net.WebProxy();
ServeurWSI wsi = new ServeurWSI();
srv.Url = "http://myServerName:8087/myServerApp/services/myService";
wsr = srv.login(wsi);
The service is called 'Extended' because I overrided the auto-generated one in order to add Cookie managment since I am using the Compact Framework. Following the sample in this thread:
https://social.msdn.microsoft.com/Forums/en-US/34d88228-0b68-4fda-a8cd-58efe6b47958/no-cookies-sessionstate-in-compact-framework?forum=vssmartdevicesvbcs
EDIT:
I made some new tests with the Web references and got it to work.
When I add the Web Reference, I have to put some Url to the Web Service. When I set it with the actual hostname instead of the 'localhost' everything is fine.
But then, since I set it manually to the real address just before the call, it shouldn't matter
srv.Url = "http://myServerName:8087/myServerApp/services/myService";
EDIT2:
I might have forgotten some specifics about my environnement.
The Web Services are exposed on my computer on some Tomcat Server.
The application I am working on is also developped on this computer (That's why I can add Web References by putting 'localhost' in the address)
The application is then deployed on a distant device (Windows CE) that will make calls the Web Services through WIFI (There, localhost wouldn't work then)
I tried calling the Web services from other computers successfully.
I'm beginning to think that there might be some differential between the called Url and the one that is set, otherwise, how would I have a difference in behaviour such as the one described in the first edit?
EDIT3:
Well..Seems like it's not a network issue but a .Net compact framework (usage?) issue...
The Url property of the Web Service implementation is simply ignored and the one in the Reference.cs is used in place.
If someone had some idea on how I could troubleshot this, I would really appreciate it.

That error means that you reached a server and the server said "no way". So you're either hitting the wrong server or the wrong port.
I find the telnet client is useful for testing stuff like this. From the command line, you can do:
telnet [servername] [port]
So something like:
telnet myServerName 8087
If it goes to a blank screen, then it connected successfully. If it does not connect, it'll tell you.
The telnet client is no longer installed by default in Windows 7+, so you'll have to install it. See here for instructions: https://technet.microsoft.com/en-ca/library/cc771275
If the connection does open, you could paste in an actual HTTP request to see what happens. A simple GET would look something like this:
GET /myServerApp/services/myService HTTP/1.1
Host: myServerName:8087

One reason for this error can be that the service binds to only a certain IP address. It could well be that the service only listens on the IP that is assigned to the host name, but not on the localhost IP (127.0.0.1).
For example:
If the host myServerName has the public IP 192.168.0.1, your service can choose to listen on all IPs assigned to the host (sometimes specifying 0.0.0.0), or it can specifically listen on 192.168.0.1 only. In that case you will not be able to connect through 127.0.0.1, because the service simply doesn't listen on that IP.
You can "use" this inverse of this feature to make a service accessible only to local clients, not on the public IP-Address, by listening on 127.0.0.1 only, but not on the public IP. This is sometimes used on Linux for example to make MySQL only accessible on the host itself.

I was starting to forget this post but I finally found the problem that was messing things up and it has nothing to do with programmation.
I was doing the calls while the device was connected to the computer via the 'Windows Mobile Device Center' allowing to access the device from Windows.
While connected, the host provided is ignored and all calls on the specified port are handled by the connected computer.
Disconnecting the device allows to communicate properly...

How can I connect a C# SSLStream client to an OpenSSL server?

I am currentry writing a C# client (with Mono using SSLStream) for an already existing OpenSSL server written in C++. I know that in theory, they should be able to communicate, but I always get an Exception:
Authentication or decryption has failed.
Which takes place in Mono.Security.Protocol.Tls.SslStreamBase.AsyncHandshakeCallback when I invoke sslStream.AuthenticateAsClient(ServerName);
I do not need client authentication, so i don't use any client certificate, and i can't load my server certificate into a client's trust store, as I can't use the command line on the client side.
On the server, I seem to receive some random data, which should not happen, as I never invoke sslStream.Write() in the client code. Maybe I don't completely understand how the handshake happens. I have an OpenSSL C++ client that works perfectly though.
Does someone know How I could get this working?
I am using, on the server side, a self-signed certificate generated by OpenSSL, which i converted to DER format.
How I proceed:
Server side
Initialize OpenSSL
Load server certificate (DER) and private key (PEM)
Open a non-SSL listening socket
As a client connects, I open a new socket which I connect to an SSL_Bio and accept the connection
Read the SSL socket for incoming data.
Client side
I am trying to connect using a temporary client adapted from the one in this topic.
Open a new TCPClient
Link a new SSLStream to it with the same validation callback as in the thread above;
Calling AuthenticateAsClient(ServerName) which brings this exception.
Invoke sslStream.Write but the execution never gets here.
Any help would be greatly appreciated as I am not sure to understand how sslStream internally works.

Ok, got it. In fact, I was setting up the BIO and the SSL variables in the wrong order. You have to create and attach your BIO to your SSL BEFORE you actually call SSL_Accept in OpenSSL, otherwise the authentication cannot complete, which seems logical.
Also, I was using SSLStream in C# on client side to send my messages, while I was using BIO_read and BIO_write on the server Side with OpenSSL.
This could not work, because BIO_read and BIO_write are no equivalent to SSL_read and SSL_write. These two functions only read and write on the underlying socket, without any encryption or decryption, making the SSL handshake almost useless (aside from checking the identity of the other end of the line).
This explains why I was not able to engage communication as the two ends did not speak the same language: one sent unencrypted messages while the other expected SSL-wrapped messages and the other way round.
The SSL_read and SSL_Write functions take care of the encryption and decryption, so they are the ones to use here. Now it works perfectly.
If you need any further details about how I did that, please comment this answer.

Listening a port in c# (not a TCP port)

My situation: I have an xspeech for voip, when there is an action about phone, the messages(packets) are sent to the xspeech interface. And from this interface the logs of these action are sent to specific IP address which is my IP address. And also these logs are sent from a specific port.
I am trying to develop an application that reads these logs(not a file). I tried TCPListener and TCPClient, they worked but not in my situation. I thought these logs are not sent from TCP port. This is the problem.

From your post I suspect it is using UDP... this would mean that you need to use UDPClient class to receive and process...
Depending on whether they offer a TAPI provider you can use:
http://www.codeproject.com/KB/IP/devangpro.aspx
http://www.codeproject.com/KB/dotnet/CShart_TAPI_3x.aspx
http://www.codeproject.com/KB/IP/Video_Voice_Conferencing.aspx
http://msdn.microsoft.com/en-us/library/ms734214.aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/ms734257%28v=vs.85%29.aspx
It may be necessary to build a SIP proxy (this would be able to generate for example "Pickup event"):
http://www.codeproject.com/KB/cs/SIP_stack_with_SIP_proxy.aspx
http://sipsorcery.codeplex.com/
http://www.independentsoft.de/sip/index.html
http://www.konnetic.com/products/products_sip_sdk_std.aspx
http://www.voiceelements.com/Products/VEToolkit.aspx
EDIT - as per comments other possibilities:
If what you try to catch is sent as syslog message then see http://michael.chanceyjr.com/useful-code/syslogd-class-for-sending-and-receiving-syslogd-events/ .
Another possibility is SNMP - for this see http://www.snmpsharpnet.com/

SIP uses UDP per default.
It's not as simple as being able to take packets from one endpoint, log them and then send them to the real destination. You'll break things like NAT handling if you do so.
You need to act as a full SIP proxy (stateful) or as a B2BUA.
The easier way is to download an existing sip-proxy and just make it log to a file and read that file.

If you're recieving the information on at your IP address then I too would have thought that TCP/IP was being used. Have you checked that your firewall isn't blovking the port in question.
I would suggest that you have another look at what protocol is being used (it may be UDP) and use the Socket class instead.

No response from sever on external IP in client-server IM app

I'm following a tutorial # http://www.geekpedia.com/tutorial239_Csharp-Chat-Part-1---Building-the-Chat-Client.html to try and gather the basics of networking. For those not wanting to hit the jump, it's a quick tut demonstrating how to program a simple client-server-model chat application.
When I try and run the code in the tut, it works fine as long as both the client and the server are on the same network, but the second I try and do it externally (getting a mate to run the client app, and running the server app my side), it all goes to pot. The fact that the code works when in the same network leads me to believe that it's not a coding issue, but an issue with the way my network is set up.
I'm trying to run the server on my IP address at port 21719, which I have opened, but still other people can't connect to my server, not able to get any form of response at all.
The code (from the tut) that is being used for the server to listen to connections is:
public void StartListening()
{
IPAddress ipaLocal = ipAddress; //ipAddress is parsed from txtIP
tlsClient = new TcpListener(ipaLocal, 21719);
tlsClient.Start();
ServRunning = true; //for the running loop
// Start the new tread that hosts the listener
thrListener = new Thread(KeepListening);
thrListener.Start();
}
Now, the tutorial does actually point out that
IPAddress ipaLocal = ipAddress;
Will cause issues on some configurations, and I'm beginning to fear that my configuration may be included in that.
So, does anyone have any solution for me?
Thanks,
Sam

What is the local IP address that you're using? (ipAddress) If it's 127.0.0.1, that's not correct (I don't know how it would work internally either, but Windows seems to use magic from time to time). Also, if you have multiple NICs in your local machine, maybe the port forwarding is only set up to forward to one of them, and you're using the IP of the other?
If that's not the problem, here are a few generic suggestions:
Grab a copy of netcat. It's a small network testing util whose only job is to form a simple TCP connection. That will allow you to eliminate your code as a variable in all this. If netcat can form a connection, then you know the problem is your code. If not, you've confirmed that it's your router.
You can use WireShark (or TShark) to look for ICMP packets. Capture ICMP packets on the remote machine. If you get "Destination Unreachable" from the router, you've again proved that it's your router.
As Spencer said you need to make sure Port Forwarding is setup on your router, to forward all packets that come in on port 21719 to your internal machine. As for exactly how to do that, it's hard to say without knowing what type of router.

Are you having people use your external (internet) IP address? (See yours here.)
Have you pinholed your router to forward all communications from port 21719 to your server?

Some tips:
What kind of operating system are you using? Please check the Scope and/or Profiles (under Advanced tab) of your firewall rule.
While your friend is trying to telnet to the port (connect to the im server) monitor the traffic using Wireshark or Network Monitor (Wireshark have problems with Vista and Win 7). If you don't see anything hitting your machine the problem is probably on the router side. Double check the settings - you said you set the forward rule (NAT) but did it also set the rule on firewall of your router?