<filter name='no-mac-spoofing' chain='mac' priority='-800'>
  <uuid>cc0b9725-b6c4-40c5-b156-8ef5e17c6b2b</uuid>
  <rule action='return' direction='out' priority='500'>
    <mac srcmacaddr='$MAC'/>
  </rule>
  <rule action='drop' direction='out' priority='500'>
    <mac/>
  </rule>
</filter>

