<filter name='testcase'>
    <uuid>d6b1a2af-def6-2898-9f8d-4a74e3c39558</uuid>
    <!-- allow incoming ICMP Echo Request -->
    <rule action='accept' direction='in' priority='500'>
        <icmp type='8'/>
    </rule>
    <!-- allow outgoing ICMP Echo Reply -->
    <rule action='accept' direction='out' priority='500'>
        <icmp type='0'/>
    </rule>
    <!-- drop all other ICMP traffic -->
    <rule action='drop' direction='inout' priority='600'>
        <icmp/>
    </rule>
</filter>