/usr/lib/firewalld/services/ Current File: //usr/lib/firewalld/services/lightning-network.xml

<?xml version="1.0" encoding="utf-8"?>
<service>
  <short>Lightning Network</short>
  <description>The default port used by Lightning Network.  Enable this option if you plan to be a Lightning Network node.</description>
  <port protocol="tcp" port="9735"/>
</service>