Detecting ISP

[mastana]

I want an application to detect which internet service provider i am using at a particular moment to log on the net(out of the many ISP I use). How can I do that??? Please HELP.

[Serge]

Here you go:

Private Const WSADescription_Len = 256
Private Const WSASYS_Status_Len = 128
Private Const WS_VERSION_REQD As Long = &H101
Private Const IP_SUCCESS As Long = 0
Private Const SOCKET_ERROR As Long = -1
Private Const AF_INET = 2

Private Type WSADATA
  wVersion As Integer
  wHighVersion As Integer
  szDescription(0 To WSADescription_Len) As Byte
  szSystemStatus(0 To WSASYS_Status_Len) As Byte
  imaxsockets As Integer
  imaxudp As Integer
  lpszvenderinfo As Long
End Type

Private Declare Function WSAStartup Lib "wsock32.dll" (ByVal VersionReq As Long, WSADataReturn As WSADATA) As Long
Private Declare Function WSACleanup Lib "wsock32.dll" () As Long
Private Declare Function inet_addr Lib "wsock32.dll" (ByVal s As String) As Long
Private Declare Function gethostbyaddr Lib "wsock32.dll" (haddr As Long, ByVal hnlen As Long, ByVal addrtype As Long) As Long
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (xDest As Any, xSource As Any, ByVal lngBytes As Long)
Private Declare Function lstrlen Lib "kernel32" Alias "lstrlenA" (lpString As Any) As Long

Public Function SocketsInitialize() As Boolean
    Dim WSAD As WSADATA
   
    SocketsInitialize = WSAStartup(WS_VERSION_REQD, WSAD) = IP_SUCCESS
End Function

Public Sub SocketsCleanup()
    If WSACleanup() <> 0 Then
        MsgBox "Windows Sockets error occurred in Cleanup.", vbExclamation
    End If
End Sub

Public Function GetHostNameFromIP(ByVal sAddress As String) As String
    Dim lngHosent As Long
    Dim lngAddress As Long
    Dim lngBytes As Long
   
    If SocketsInitialize() Then
        lngAddress = inet_addr(sAddress)
        If lngAddress <> SOCKET_ERROR Then
            lngHosent = gethostbyaddr(lngAddress, 4, AF_INET)
            If lngHosent <> 0 Then
                'convert address and
                'get resolved hostname
                CopyMemory lngHosent, ByVal lngHosent, 4
                lngBytes = lstrlen(ByVal lngHosent)
         
                If lngBytes > 0 Then
                    sAddress = Space$(lngBytes)
                    CopyMemory ByVal sAddress, ByVal lngHosent, lngBytes
                    GetHostNameFromIP = sAddress
                End If
         
            Else
                MsgBox "Call to gethostbyaddr failed."
            End If
      
            SocketsCleanup
      
        Else
            MsgBox "String passed is an invalid IP."
        End If
   
    Else
        MsgBox "Sockets failed to initialize."
    End If
End Function

Private Sub Command1_Click()
    Text1 = GetHostNameFromIP(Text1)
End Sub

Type in the IP address in the textbox, press a button and you get the DNS for that IP, i.e vb-world.net etc.