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

//usr/lib/firewalld/helpers/ftp.xml

 <?xml version="1.0" encoding="utf-8"?>
<helper module="nf_conntrack_ftp">
  <port protocol="tcp" port="21"/>
</helper>