Function ValidarIP(ByVal IPaValidar As String) As Boolean
    On Error GoTo Error_ValidarIP
    Dim ByteIP As String, FinValidar As Boolean, cIP As Integer, cIPBis As Integer
    
    If Not IsNumeric(IPaValidar) Then Exit Function
    ValidarIP = True
    cIP = 1
    FinValidar = False
    Do
        cIPBis = InStr(cIP, IPaValidar, ".")
        If cIPBis = 0 Then
            cIPBis = Len(IPaValidar) + 1
            FinValidar = True
        End If
        
        ' Le restamos la posicion inicial para obtener el número
        ByteIP = Mid(IPaValidar, cIP, cIPBis - cIP)
        If ByteIP < 0 Or ByteIP > 256 Then ValidarIP = False
        cIP = cIPBis + 1
    Loop Until FinValidar
Exit Function
Error_ValidarIP:
    ValidarIP = False
End Function