Red Hat Enterprise Linux 9 Essentials Book now available.
Purchase a copy of Red Hat Enterprise Linux 9 (RHEL 9) Essentials
Red Hat Enterprise Linux 9 Essentials Print and eBook (PDF) editions contain 34 chapters and 298 pages
iptables
[root@myServer ~] # service iptables restart
[root@myServer ~] # chkconfig --level 345 iptables on