Option Explicit
 
Private Const WS_VERSION_REQD           As Long = &H202
Private Const SOCKET_ERROR              As Long = -1
Private Const IP_SUCCESS                As Long = 0&
Private Const WSADescription_Len        As Long = 255   '256, 0-based
Private Const WSASYS_Status_Len         As Long = 127   '128, 0-based
Private Const AF_INET                   As Integer = 2
 
Private Type WSADATA
   nVersion         As Integer
   nHighVersion     As Integer
   yDescription(0 To WSADescription_Len)   As Byte
   ySystemStatus(0 To WSASYS_Status_Len)   As Byte
   nMaxSockets      As Integer
   nMaxUdp          As Integer
   lVvenderInfo   As Long
End Type
 
Private Type sockaddr_in
    sin_family  As Integer
    sin_port    As Integer
    sin_addr    As Long
    sin_zero(0 To 8)    As Byte
End Type
 
Private Declare Function WSAStartup Lib "WS2_32" (ByVal VersionReq As Long, _
  WSADataReturn As WSADATA) As Long
Private Declare Function WSACleanup Lib "WS2_32" () As Long
Private Declare Function inet_addr Lib "WS2_32" (ByVal s As String) As Long
Private Declare Function getnameinfo Lib "WS2_32" (addr As Any, ByVal iLen As _
  Long, ByRef host As String, ByVal HostLen As Long, ByRef serv As String, _
  ByVal servlen As Long, ByVal Flags As Long) As Long
Private Declare Sub ZeroMemory Lib "KERNEL32" Alias "RtlZeroMemory" (dest As _
Any, ByVal numBytes As Long)
 
Private Sub Form_Load()
 
    Dim llIP            As Long
    Dim ltWSAD          As WSADATA
    Dim ltSockAddr_in   As sockaddr_in
    Dim lsHostname      As String
    Dim llReturnCode    As Long
 
    If WSAStartup(WS_VERSION_REQD, ltWSAD) = IP_SUCCESS Then
        llIP = inet_addr("209.85.129.147")                      'convert string 
        ' google.de ip to long
        If llIP <> SOCKET_ERROR Then
            ZeroMemory ltSockAddr_in, CLng(Len(ltSockAddr_in))  'initialize 
            ' structure
            ltSockAddr_in.sin_family = AF_INET
            ltSockAddr_in.sin_addr = llIP                       'ip address
            lsHostname = String$(1025, 0)                       'reserve space 
            ' für hostname info
            llReturnCode = getnameinfo(ltSockAddr_in, Len(ltSockAddr_in), _
              lsHostname, Len(lsHostname), 0, 0, 0)
            MsgBox CStr(llReturnCode)
        Else
            MsgBox "Invalid IP"
        End If
        WSACleanup
    Else
        MsgBox "Error Startup"
    End If
 
End Sub