Why does the unable to read data from the transport connection error occur?

Question

I don't know what I'm doing wrong, but I've already lost a couple of days struggling with this. Here is my command line:

tcpClient = (TcpClient)client;
 clientStream = tcpClient.GetStream();
 sr = new StreamReader(clientStream);
 sw = new StreamWriter(clientStream);
 
 // line 96: 
 a = sr.ReadLine();

This returns:

Couldn't get stream from client or login failed: System.IO.IOException:
Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.

I don't have any experience with the “unable to read data from the transport connection.” In this case, how should I change?

hdtutoria · Accepted Answer

The cause: This error typically indicates that the target machine is running, but the service you're trying to connect to isn't. (It either came to a halt, crashed, or is preoccupied with another request.) The solution: The issue was rectified by adding the following line before making the call:

System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;

Léo Gauthier · Answer

This error occurred when I called a web-service. This issue also had to do with transport level security. Although I could call the web service through a website project it would not work if I used the same code in a test program. I would then get this message as a WebException. The issue was resolved by adding the following line before calling the web-service:

System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;

Edit

System.Net.ServicePointManager.SecurityProtocol - This property selects the version of the Secure Sockets Layer (SSL) or Transport Layer Security (TLS) protocol to use for new connections that use the Secure Hypertext Transfer Protocol (HTTPS) scheme only; existing connections are not changed.

When selecting the protocol version, I think the SecurityProtocol configuration should be considered.

TLS handshake - This protocol is used to exchange all the information required by both sides for the exchange of the actual application data by TLS.

ClientHello - A client sends a ClientHello message specifying the highest TLS protocol version it supports ...

ServerHello - The server responds with a ServerHello message, containing the chosen protocol version ... The chosen protocol version should be the highest that both the client and server support. For example, if the client supports TLS version 1.1 and the server supports version 1.2, version 1.1 should be selected; version 1.2 should not be selected.

Aria Brown · Answer

This error occurred when I called a web-service. This issue also had to do with transport level security. Although I could call the web service through a website project it would not work if I used the same code in a test program. I would then get this message as a WebException. The issue was resolved by adding the following line before calling the web-service:

System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;

Edit

System.Net.ServicePointManager.SecurityProtocol - This property selects the version of the Secure Sockets Layer (SSL) or Transport Layer Security (TLS) protocol to use for new connections that use the Secure Hypertext Transfer Protocol (HTTPS) scheme only; existing connections are not changed.

When selecting the protocol version, I think the SecurityProtocol configuration should be considered.

TLS handshake - This protocol is used to exchange all the information required by both sides for the exchange of the actual application data by TLS.

ClientHello - A client sends a ClientHello message specifying the highest TLS protocol version it supports ...

ServerHello - The server responds with a ServerHello message, containing the chosen protocol version ... The chosen protocol version should be the highest that both the client and server support. For example, if the client supports TLS version 1.1 and the server supports version 1.2, version 1.1 should be selected; version 1.2 should not be selected.

Noa Anderson · Answer

I'm not sure which of these blog posts helped me, but one did.

http://briancaos.wordpress.com/2012/07/06/unable-to-read-data-from-the-transport-connection-the-connection-was-closed/

I found the trick to help me quit using WebRequests and instead use a HttpWebRequest. I can play with three important settings using the HttpWebRequest:

And

http://briancaos.wordpress.com/2012/06/15/an-existing-connection-was-forcibly-closed-by-the-remote-host/

STEP 1 - Disable KeepAlive
STEP 2 - Set the ProtocolVersion to Version10
STEP 3 Limiting the number service points

Sign Up

Sign In

Forgot Password

ITtutoria Latest Questions

Why does the unable to read data from the transport connection error occur?