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/services/telnet.xml

 <?xml version="1.0" encoding="utf-8"?>
<service>
  <short>Telnet</short>
  <description>Telnet is a protocol for logging into remote machines. It is unencrypted, and provides little security from network snooping attacks. Enabling telnet is not recommended. You need the telnet-server package installed for this option to be useful.</description>
  <port port="23" protocol="tcp"/>
</service>