Restart Iptables Firewall On A CentOS Linux Server

I am a new CentOS Linux user and installed it on HP server. I updated /etc/sysconfig/iptables firewall config file. How do I restart a firewall on CentOS Linux version 5/6? How can I use command line to restart iptables on a CentOS server?

Tutorial details
Difficulty level	Easy
Root privileges	Yes
Requirements	None
Est. reading time	1m

You can easily start or stop or restart firewall on a CentOS / Fedora / RHEL / Red Hat Linux server using the following syntax. You need to login as root user.

CentOS Linux restart iptables command

The syntax is as follows to restart an IPv4 iptables based firewall:
# service iptables restart

The syntax is as follows to restart an IPv6 iptables based firewall:
# service ip6tables restart

CentOS Linux stop iptables command

The syntax is as follows to stop an IPv4 iptables based firewall:
# service iptables stop

The syntax is as follows to stop an IPv6 iptables based firewall:
# service ip6tables stop

CentOS Linux start iptables command

The syntax is as follows to start an IPv4 iptables based firewall:
# service iptables start

The syntax is as follows to start an IPv6 iptables based firewall:
# service ip6tables start

CentOS Linux get status of iptables command

The syntax is as follows to status of an IPv4 iptables based firewall:
# service iptables status

The syntax is as follows to status of an IPv6 iptables based firewall:
# service ip6tables status

Category	List of Unix and Linux commands
Disk space analyzers	ncdu • pydf
File Management	cat
Firewall	Alpine Awall • CentOS 8 • OpenSUSE • RHEL 8 • Ubuntu 16.04 • Ubuntu 18.04 • Ubuntu 20.04
Network Utilities	NetHogs • dig • host • ip • nmap
OpenVPN	CentOS 7 • CentOS 8 • Debian 10 • Debian 8/9 • Ubuntu 18.04 • Ubuntu 20.04
Package Manager	apk • apt
Processes Management	bg • chroot • cron • disown • fg • jobs • killall • kill • pidof • pstree • pwdx • time
Searching	grep • whereis • which
User Information	groups • id • lastcomm • last • lid/libuser-lid • logname • members • users • whoami • who • w
WireGuard VPN	Alpine • CentOS 8 • Debian 10 • Firewall • Ubuntu 20.04