Wake On LAN not working

Public Class Form1

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        SendMagicPacket("IP", "MAC Addr", "Sub Net") 'Remote PC details
    End Sub

    Public Sub SendMagicPacket(ByVal ipAddress As String, ByVal strMacAddress As String, ByVal strLanSubnet As String)
        'SET THESE VARIABLES TO REAL VALUES
        Dim MacAddress As String = String.Empty
        Dim WANIPAddr As String = String.Empty
        Dim LanSubnet As String = String.Empty
        Dim strBroadcast As String = String.Empty

        'Ports to send magic packet to.
        Dim Port As Integer = 9
        Dim AltPort As Integer = 7

        Dim udpClient As New System.Net.Sockets.UdpClient
        Dim buf(101) As Char
        Dim sendBytes As [Byte]() = System.Text.Encoding.ASCII.GetBytes(buf)

        MacAddress = strMacAddress
        WANIPAddr = ipAddress
        LanSubnet = strLanSubnet

        For x As Integer = 0 To 5
            sendBytes(x) = CByte("&HFF")
        Next

        MacAddress = MacAddress.Replace("-", "").Replace(":", "")

        Dim i As Integer = 6

        For x As Integer = 1 To 16
            sendBytes(i) = CByte("&H" + MacAddress.Substring(0, 2))
            sendBytes(i + 1) = CByte("&H" + MacAddress.Substring(2, 2))
            sendBytes(i + 2) = CByte("&H" + MacAddress.Substring(4, 2))
            sendBytes(i + 3) = CByte("&H" + MacAddress.Substring(6, 2))
            sendBytes(i + 4) = CByte("&H" + MacAddress.Substring(8, 2))
            sendBytes(i + 5) = CByte("&H" + MacAddress.Substring(10, 2))
            i += 6
        Next

        Dim myAddress As String

        Try
            myAddress = Net.IPAddress.Parse(WANIPAddr).ToString
        Catch ex As Exception
            MsgBox("Packet send failed. see log")
            'log("Magic packet failed! ip address appears to be invalid! error: " & ex.Message)
            Exit Sub
        End Try

        If myAddress = String.Empty Then
            MessageBox.Show("Invalid IP address/Host Name given")
            Return
        End If

        Dim mySubnetArray() As String

        mySubnetArray = LanSubnet.Split(".")

        strBroadcast = CalculateBroadCastAddress(ipAddress, strLanSubnet)

        myAddress = WANIPAddr

        Try
            'log("Magic Packet Sent with data - ip:" & ipAddress & ", broadcast: " & strBroadcast & ", mac: " & strMacAddress & ", subnet: " & strLanSubnet)

            'Send magic packet to broadcast ip
            udpClient.Send(sendBytes, sendBytes.Length, strBroadcast, Port)
            udpClient.Send(sendBytes, sendBytes.Length, strBroadcast, AltPort)

            'Send magic packet to PC's ip
            udpClient.Send(sendBytes, sendBytes.Length, ipAddress, Port)
            udpClient.Send(sendBytes, sendBytes.Length, ipAddress, AltPort)

            udpClient = Nothing
            MsgBox("Magic Packet Sent! Computer should power on IF wake-on-lan is enabled.")

            Shell("ping -t " & ipAddress, AppWinStyle.NormalFocus)
        Catch ex As Exception
            MsgBox("Error sending macgic packet. error: " & ex.Message)
        End Try

    End Sub

    Public Function CalculateBroadCastAddress(ByVal currentIP As String, ByVal ipNetMask As String) As String
        Dim strCurrentIP As String() = currentIP.ToString().Split(".")
        Dim strIPNetMask As String() = ipNetMask.ToString().Split(".")
        Dim arBroadCast As ArrayList = New ArrayList()

        Dim iTotalSubnets As Integer = 2 ^ BorrowedBits(strIPNetMask(3))
        Dim iHosts As Integer = 2 ^ (8 - BorrowedBits(strIPNetMask(3)))
        Dim iSubNetNum As Integer
        Dim iIPOctet As Integer = strCurrentIP(3)

        If iIPOctet / iHosts < 1 Then
            iSubNetNum = 0
        Else
            iSubNetNum = (iIPOctet / iHosts) - ((iIPOctet / iHosts) Mod 1)
        End If

        For i As Integer = 0 To 3
            If i <> 3 Then
                arBroadCast.Add(strCurrentIP(i))
            Else
                arBroadCast.Add((iHosts * iSubNetNum) + (iHosts - 1))
            End If
        Next

        Return arBroadCast(0) & "." & arBroadCast(1) & "." & arBroadCast(2) & "." & arBroadCast(3)

    End Function

    Function BorrowedBits(ByVal iNum As Int32) As Int32
        Select Case iNum
            Case 255
                Return 8
            Case 254
                Return 7
            Case 252
                Return 6
            Case 248
                Return 5
            Case 240
                Return 4
            Case 224
                Return 3
            Case 192
                Return 2
            Case 128
                Return 1
            Case 0
                Return 0
        End Select
    End Function


End Class