如何实现根据网络地址和掩码，自动计算可用IP地址范围？

注意最后一个是广播地址，同样不是主机IP

Public Sub listIPrange(sNetID As String, sMask As String)
    Dim nNet(4) As Integer
    Dim nMask(4) As Integer
    Dim nIP(4) As Integer
    Dim i As Integer
   
    Dim a() As String, b() As String
    a = Split(sNetID, ".")
    b = Split(sMask, ".")
   
    For i = 0 To 3
        nNet(i) = CByte(a(i))
        nMask(i) = Not CByte(b(i))
        nIP(i) = 0
        Debug.Print nMask(i)
    Next i
   
    nIP(3) = 2
    Do While nIP(0) <= nMask(0)
        Do While nIP(1) <= nMask(1)
            Do While nIP(2) <= nMask(2)
                Do While nIP(3) <= nMask(3)
                    Debug.Print nIP(0) + nNet(0);
                    Debug.Print nIP(1) + nNet(1);
                    Debug.Print nIP(2) + nNet(2);
                    Debug.Print nIP(3) + nNet(3)
                    nIP(3) = nIP(3) + 1
                Loop
                nIP(3) = 0
                nIP(2) = nIP(2) + 1
            Loop
            nIP(2) = 0
            nIP(1) = nIP(1) + 1
        Loop
        nIP(1) = 0
        nIP(0) = nIP(0) + 1
    Loop
End Sub