Bueno pues hice este pequeño modulo para comprobar la IP publica desde el VB conectándose a la web de: ip-adress.com y descargando el código de fuente. No es ninguna ciencia pero a mas de alguien le sirve.

 
Option Explicit
 
'--------------------------------------------
'   Autor   : SquX
'   Nombre  : mIP
'   Funcion : Optener el IP publico
'--------------------------------------------
 
Private Const INTERNET_OPEN_TYPE_DIRECT             As Integer = 1
Private Const INTERNET_OPEN_TYPE_PROXY              As Integer = 3
Private Const INTERNET_FLAG_RELOAD                  As Long = &H80000000
Private Const INTERNET_FLAG_NO_CACHE_WRITE          As Long = &H4000000
 
Private Declare Function InternetOpen Lib "wininet" Alias "InternetOpenA" (ByVal sAgent As String, ByVal lAccessType As Long, ByVal sProxyName As String, ByVal sProxyBypass As String, ByVal lFlags As Long) As Long
Private Declare Function InternetCloseHandle Lib "wininet" (ByVal hInet As Long) As Integer
Private Declare Function InternetReadFile Lib "wininet" (ByVal hFile As Long, ByVal sBuffer As String, ByVal lNumBytesToRead As Long, lNumberOfBytesRead As Long) As Integer
Private Declare Function InternetOpenUrl Lib "wininet" Alias "InternetOpenUrlA" (ByVal hInternetSession As Long, ByVal lpszUrl As String, ByVal lpszHeaders As String, ByVal dwHeadersLength As Long, ByVal dwFlags As Long, ByVal dwContext As Long) As Long
 
Public Function sIP() As String
 
    sIP = Dividir(Code("http://www.ip-adress.com"), "<h2>My IP address is: ", "</h2>")
 
End Function
 
Public Function Code(sURL As String) As String ' // Basado en ejemplo en recursosvisualbasic.com.ar
 
    Dim sBuff   As String * 100
    Dim sOpen   As Long
    Dim sFile   As Long
    Dim sRet    As Long
 
    sOpen = InternetOpen("SquX", INTERNET_OPEN_TYPE_DIRECT, vbNullString, vbNullString, 0)
 
    If sOpen <> 0 Then
 
        sFile = InternetOpenUrl(sOpen, sURL, vbNullString, ByVal 0&, INTERNET_FLAG_NO_CACHE_WRITE, ByVal 0&)
 
        If sFile <> 0 Then
 
            Do
 
                Call InternetReadFile(sFile, sBuff, 100, sRet)
 
                Code = Code & Mid$(sBuff, 1, sRet)
 
                If sRet = 0 Then
 
                    Exit Do
 
                End If
 
            Loop
 
            Call InternetCloseHandle(sFile)
            Call InternetCloseHandle(sOpen)
 
        End If
 
    End If
 
End Function
 
Public Function Dividir(Texto As String, Delimitador1 As String, Delimitador2 As String) As String
 
    Dim sData() As String
 
    sData() = Split(Texto, Delimitador1)
    sData() = Split(sData(1), Delimitador2)
 
    Dividir = sData(0)
 
End Function
 
 

Uso:

 
Option Explicit
 
Private Const MB_ICONINFORMATION            As Long = &H40&
 
Private Declare Function MessageBox Lib "user32" Alias "MessageBoxA" (ByVal hwnd As Long, ByVal lpText As String, ByVal lpCaption As String, ByVal wType As Long) As Long
 
Private Sub Form_Load()
 
    Call MessageBox(Me.hwnd, "Mi ip es: " & sIP, "IP", MB_ICONINFORMATION)
 
End Sub
 
 

Espero criticas

Hay un error de logica ahi.

A ti te conozco, no?