VB.Net code for Wake On LAN

Last Updated: 11/5/13

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

Update 11/5/2013 -- I was told this function works better, insert as needed:

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 strWildcard As String() = {255, 255, 255, 255}

For i As Integer = 0 To 3
strWildcard(i) = (strWildcard(i) - strIPNetMask(i))
If strWildcard(i) = 0 And strWildcard(i) 255 Then
arBroadCast.Add(strCurrentIP(i))
ElseIf strWildcard(i) = 255 Then
arBroadCast.Add(255)
ElseIf strWildcard(i) 0 And strWildcard(i) 255 Then
arBroadCast.Add((((strCurrentIP(i) \\ (strWildcard(i) + 1)) * (strWildcard(i) + 1)) + (strWildcard(i))))
End If
Next

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

End Function

Keywords: vb.net clr code for wake on lan magic packet udp broadcast