Public Shared Function MACAdresse(ByVal NetzwerkAdapter As _
      NetworkInformation.NetworkInterface) As String
        Try
            Dim PhysikalischeAdresse As Net.NetworkInformation.PhysicalAddress _
              = NetzwerkAdapter.GetPhysicalAddress
            Dim MACBytes() As Byte = PhysikalischeAdresse.GetAddressBytes
            Dim oMACAdresse As String = String.Empty
            For Each oByte As Byte In MACBytes
                oMACAdresse &= oByte.ToString("X2")
            Next oByte
            oMACAdresse = oMACAdresse.Insert(2, "-")
            oMACAdresse = oMACAdresse.Insert(5, "-")
            oMACAdresse = oMACAdresse.Insert(8, "-")
            oMACAdresse = oMACAdresse.Insert(11, "-")
            oMACAdresse = oMACAdresse.Insert(14, "-")
            Return oMACAdresse
        Catch Fehler As Exception
            Return String.Empty
        End Try
    End Function

 
 Dim NetzwerkSchnittstellen As Net.NetworkInformation.NetworkInterface = _
   Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces(0)