/usr/lib/firewalld/icmptypes/ Current File: //usr/lib/firewalld/icmptypes/timestamp-request.xml

<?xml version="1.0" encoding="utf-8"?>
<icmptype>
  <short>Timestamp Request</short>
  <description>This message is used for time synchronization.</description>
  <destination ipv4="yes"/>
  <destination ipv6="no"/>
</icmptype>