I've desperately scoured the internet for code on obtaining the MAC Addresss of a client, and the code I have found (2 functions below) works well for a Windows box, but
not for a MAC client.
Does anyone know of how I can get MAC address of a OSX or MAC client with Silverlight?

 Declare Function SendARP Lib "iphlpapi.dll" (ByVal DestIP As UInt32, ByVal SrcIP As UInt32, ByVal pMacAddr As Byte(), ByRef PhyAddrLen As Integer) As Integer

    Public Shared Function GetMAC(ByVal IPAddress As String) As String
        Dim addr As Net.IPAddress = Net.IPAddress.Parse(IPAddress)
        Dim mac() As Byte = New Byte(6) {}
        Dim len As Integer = mac.Length
        SendARP(CUInt(addr.Address), 0, mac, len)
        Dim macAddress As String = BitConverter.ToString(mac, 0, len)
        Return macAddress.Replace("-", "")
    End Function

    Public Shared Function GetMac() As String
        Dim myResult As String = ""
            Using wmiLocator = Runtime.InteropServices.Automation.AutomationFactory.CreateObject("WbemScripting.SWbemLocator")
                wmiLocator.Security_.ImpersonationLevel = 3
                wmiLocator.Security_.AuthenticationLevel = 4
                Dim wmiService = wmiLocator.ConnectServer(".", "root\cimv2")
                Dim wmiQuery = "SELECT MACAddress FROM Win32_NetworkAdapterConfiguration where IPEnabled=true"
                Dim queryResults = wmiService.ExecQuery(wmiQuery)
                For Each o As Object In queryResults
                    myResult = o.MACAddress.ToString.Replace(":", "")
                    Exit For
            End Using
        Catch ex As Exception

        End Try

        Return myResult

    End Function