freeswitch/conf/vanilla/autoload_configs/event_multicast.conf.xml

<configuration name="event_multicast.conf" description="Multicast Event">
  <settings>
    <param name="address" value="225.1.1.1"/>
    <param name="port" value="4242"/>
    <param name="bindings" value="all"/>
    <param name="ttl" value="1"/>
    <!-- <param name="loopback" value="no"/>-->
    <!-- Uncomment this to enable pre-shared key encryption on the packets. -->
    <!-- For this option to work, you'll need to have the openssl development -->
    <!-- headers installed when you ran ./configure -->
    <!-- <param name="psk" value="ClueCon"/> -->
  </settings>
</configuration>