linux关闭防火墙命令

1.  Linux系统：Red Hat Enterprise Linux Server release 6.5 (Santiago)

临时关闭防火墙命令：
service iptables stop
service ip6tables stop

永久关闭防火墙命令：
chkconfig iptables off
chkconfig ip6tables off

查看防火墙状态命令：
service iptables status

[root@hadoop ~]# cat /etc/redhat-release 
Red Hat Enterprise Linux Server release 6.5 (Santiago)

[root@hadoop ~]# service iptables stop
iptables: Setting chains to policy ACCEPT: filter          [  OK  ]
iptables: Flushing firewall rules:                         [  OK  ]
iptables: Unloading modules:                               [  OK  ]
[root@hadoop ~]# service ip6tables stop
ip6tables: Setting chains to policy ACCEPT: filter         [  OK  ]
ip6tables: Flushing firewall rules:                        [  OK  ]
ip6tables: Unloading modules:                              [  OK  ]

[root@hadoop ~]# service iptables status
iptables: Firewall is not running.
[root@hadoop ~]# service ip6tables status
ip6tables: Firewall is not running.

[root@hadoop ~]# chkconfig iptables off
[root@hadoop ~]# chkconfig ip6tables off

2.  linux系统：CentOS Linux release 7.5.1804 (Core)

前面说的几个命令，我在centos 7上用着都失效了。网上说，centos从7开始默认用的是firewalld，这个是基于iptables的，虽然有iptables的核心，但是iptables的服务是没安装的。所以你只要停止firewalld服务即可

[root@hadoop ~]# sudo systemctl stop firewalld.service && sudo systemctl disable firewalld.service
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.

如果你要改用iptables的话，需要安装iptables服务，并对命令做一些修改

[root@hadoop ~]# service iptables stop #命令失效
Redirecting to /bin/systemctl stop iptables.service
Failed to stop iptables.service: Unit iptables.service not loaded.

[root@hadoop ~]#  yum install iptables-services 
[root@hadoop ~]# /bin/systemctl stop iptables.service
[root@hadoop ~]# /bin/systemctl stop ip6tables.service

永久关闭防火墙

[root@hadoop ~]# chkconfig iptables off #命令失效
Note: Forwarding request to 'systemctl disable iptables.service'.

[root@hadoop ~]# systemctl disable iptables.service
[root@hadoop ~]# systemctl disable ip6tables.service

查看防火墙是否关闭

[root@hadoop ~]# firewall-cmd --state
not running

总结：centos 7系统关闭防火墙有2种方式：

方式1：
关闭防火墙：systemctl stop firewalld.service
永久关闭防火墙：systemctl disable firewalld.service

方式2：
首先安装iptables服务：yum install iptables-services 
关闭防火墙：/bin/systemctl stop iptables.service && /bin/systemctl stop ip6tables.service
永久关闭防火墙：systemctl disable iptables.service && systemctl disable ip6tables.service
查看防火墙是否关闭：firewall-cmd --state