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

Question

First I explain the concept:

I have two system both system have static ip address.

Desktop application developed in vb.net and back end is sql server.

Webapplication is developed in asp.net and backend is sql server.

I run desktop application in system1. Webapplication run in another system2.

When I send http request from system2 to system1 they response my request. Sometimes the remote server not connected because port 80 is blocked. That time it display the error message "No connection could be made because the target machine actively refused it".

My Request Coding Example:

    Dim uri1 As New Uri("http://xx.xxx.xx.xx/SysConnectionStatus/")
    If (uri1.Scheme = Uri.UriSchemeHttp) Then
        Dim wrequest1 As HttpWebRequest = HttpWebRequest.Create(uri1)
        wrequest1.Method = WebRequestMethods.Http.Get
        Dim wresponse1 As HttpWebResponse = wrequest1.GetResponse()
        Dim reader1 As New StreamReader(wresponse1.GetResponseStream())
        Dim tmp2 As String = reader1.ReadToEnd()
        wresponse1.Close()
        Response.Write(tmp2)
    End If

Response for that request is

   ALIVE

When I restart my system1 the port 80 is opened. After some request I send then it will be blocked.

I already check the following things

  1.Windows firewall is disabled.
  2.No antivirus is installed
  3.No virus found in both system.

So what is the problem? How to solve this problem?

Antony Scott Antony Scott · Accepted Answer · 2011-08-16T19:18:14

If you're using skype that can grab port 80 before IIS manages to get it, but IIS won't tell you there was a problem. To fix, just go into the advanced connection settings in skype and untick the port 80 box.

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

When I restart my system1 the port 80 is opened. After some request I send then it will be blocked.

1 Answers