Linux vacca.o2switch.net 4.18.0-553.123.2.lve.el8.x86_64 #1 SMP Thu May 7 23:17:13 UTC 2026 x86_64

//lib/firewalld/icmptypes/host-unreachable.xml

 <?xml version="1.0" encoding="utf-8"?>
<icmptype>
  <short>Host Unreachable</short>
  <description>This error message is sent if the destination host is unreachable.</description>
  <destination ipv4="yes"/>
  <destination ipv6="no"/>
</icmptype>