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.