system.net.webexception:the remote server returned an error 417 expectation failed

Question

Hi All,

I am getting the following error when I am sending an SMS through http webrequest from my service :

system.net.webexception:the remote server returned an error 417 expectation failed. we are using proxyserver.
I have tried changing the machine.config with the following settings, still no success.

<system.net>
<settings>
<servicepointmanager expect100continue="false" />
</settings>
</system.net>

Rams · Answer

this also didnot work. Thanks for your fast reply. iam stuck up with the following error : "system.net.webexception:the remote server returned an error 417 expectation failed at MBS.SmsMgr.SendSMS(Object stringPost) at MBS.Dispatcher.CommonProcedures.SendSMS(CommonProcedures objparams)". Please do find the code below : Public Function SendSMS( ByVal stringPost As System.Object) As String Implements ISmsMgr.sendSMS Dim strReturnValue As String = String .Empty Dim objWebRequest As HttpWebRequest = Nothing Dim objWebResponse As HttpWebResponse = Nothing Dim objStreamWriter As StreamWriter = Nothing Dim objStreamReader As StreamReader = Nothing Try Dim strProxyURL As String = String .Empty Dim iProxyPort As Integer = 0 If Not ConfigurationManager.AppSettings.Item( "ProxyURL" ) Is Nothing Then strProxyURL = ConfigurationManager.AppSettings.Item( "ProxyURL" ).ToString.Trim End If If Not ConfigurationManager.AppSettings.Item( "ProxyPort" ) Is Nothing Then iProxyPort = CInt (ConfigurationManager.AppSettings.Item( "ProxyPort" ).ToString.Trim) End If Dim strSMSDialerConnectionName As String = ConfigurationManager.AppSettings( "SMSDialerConnectionName" ) Dim iAvailConType As Integer = DetectConnection() If iAvailConType = enmConnectionType.NOTCONNECTED Then ' If not connected, 'Then detect the Modem connection and Dialp up. If Not String .IsNullOrEmpty(strSMSDialerConnectionName) Then Dim chSplit() As Char = { ";" } Dim strDialeConnections() As String = strSMSDialerConnectionName.Split(chSplit) If strDialeConnections.Length > 0 Then For i = 0 To strDialeConnections.Length - 1 If DialupConnection(strDialeConnections(i)) Then iAvailConType = enmConnectionType.MODEM strProxyURL = iProxyPort = 0 String .Empty If Not ConfigurationManager.AppSettings.Item( "DailUpProxyURL" ) Is Nothing Then strProxyURL = ConfigurationManager.AppSettings.Item( "DailUpProxyURL" ).ToString.Trim End If If Not ConfigurationManager.AppSettings.Item( "DailUpProxyPort" ) Is Nothing Then iProxyPort = CInt (ConfigurationManager.AppSettings.Item( "DailUpProxyPort" ).ToString.Trim) End If Exit For End If Next End If End If End If If iAvailConType enmConnectionType.NOTCONNECTED Then objWebRequest = Dim bytesToSend As Byte () = Encoding.UTF8.GetBytes(stringPost) Dim strSMSApi As String = ConfigurationManager.AppSettings.Item( "SMSApi" ).ToString DirectCast (WebRequest.Create((strSMSApi & "?" ) + stringPost.ToString()), HttpWebRequest) 'add eventvwr : laxman EventLog.WriteEntry( "SENDSMS.strSMSApi " , (strSMSApi & "?" ) + stringPost.ToString()) '(strSMSApi & "?") + stringPost.ToString() objWebRequest.Method = "POST" If ( Not String .IsNullOrEmpty(strProxyURL.Trim)) Then objProxy = objProxy.Credentials = CredentialCache.DefaultNetworkCredentials objWebRequest.Proxy = objProxy New WebProxy(strProxyURL, iProxyPort) End If objWebRequest.ContentLength = bytesToSend.Length objWebRequest.ContentType = "application/x-www-form-urlencoded" objStreamWriter = objStreamWriter.Write(stringPost) objStreamWriter.Flush() objStreamWriter.Close() objWebResponse = objStreamReader = strReturnValue = objStreamReader.ReadToEnd() objStreamReader.Close() New StreamWriter(objWebRequest.GetRequestStream()) DirectCast (objWebRequest.GetResponse(), HttpWebResponse) New StreamReader(objWebResponse.GetResponseStream())

Priya Linge · Answer

Hi Ram, Please see below link. http://code.google.com/p/duplicati/issues/detail?id=378 . Hope it will help you to solve the error. Thanks.

Rams · Answer

Hi, Thanks for the reply.. we tested the same service in our network..it is showing succesfull..but the client is using a proxy server which i think is creating a problem..

Zoran Horvat · Answer

Can you read HttpWebRequest's Expect property and paste it here? That should be the root cause of the problem - web request is sending something in the Expect HTTP header and remote Web server is unable to comply so it responds with 417 error. Give us precise Expect value you're sending. Zoran

system.net.webexception:the remote server returned an error 417 expectation failed

Answers (4)