How to turn off the firewall in linux

1) Take effect after reboot
On: chkconfig iptables on
Off: chkconfig iptables off

2) Immediately effective, invalid after restart
Start: service iptables start
Shutdown: service iptables stop

It should be noted that other services under Linux can be opened and closed with the above commands.

When the firewall is turned on, do the following settings to open the relevant ports,
Modify the /etc/sysconfig/iptables file and add the following:
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT