[root@rhel7 ~]# cat /etc/redhat-release

Red Hat Enterprise Linux Server release 7.0 (Maipo)

[root@rhel7 ~]# service iptables stop

Redirecting to /bin/systemctl stop  iptables.service

[root@rhel7 ~]# /etc/init.d/iptables stop

-bash: /etc/init.d/iptables: No such file or directory

[root@CTU1000094955 ~]#  cat /etc/redhat-release

CentOS Linux release 7.2.1511 (Core)

[root@CTU1000094955 ~]# service iptables stop

Redirecting to /bin/systemctl stop  iptables.service

Failed to stop iptables.service: Unit iptables.service not loaded.

[root@CTU1000094955 ~]# /etc/init.d/iptables stop

-bash: /etc/init.d/iptables: No such file or directory

[root@CTU1000094955 ~]# systemctl list-unit-files|grep firewall

firewalld.service                           disabled

启动一个服务：systemctl start firewalld.service

关闭一个服务：systemctl stop firewalld.service

重启一个服务：systemctl restart firewalld.service

显示一个服务的状态：systemctl status firewalld.service

在开机时启用一个服务：systemctl enable firewalld.service

在开机时禁用一个服务：systemctl disable firewalld.service

查看服务是否开机启动：systemctl is-enabled firewalld.service;echo $?

查看已启动的服务列表：systemctl list-unit-files|grep enabled

[root@CTU1000094955 ~]# systemctl stop firewalld.service

[root@CTU1000094955 ~]# systemctl list-unit-files |grep firewall

firewalld.service                           disabled

[root@CTU1000094955 ~]# firewall-cmd --permanent --list-port

FirewallD is not running

[root@CTU1000094955 ~]# systemctl status firewalld.service

?.firewalld.service - firewalld - dynamic firewall daemon

   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)

   Active: inactive (dead)

Nov  :: CTU1000094955 systemd[]: Starting firewalld - dynamic firewall daemon...

Nov  :: CTU1000094955 systemd[]: Started firewalld - dynamic firewall daemon.

Nov  :: CTU1000094955 systemd[]: Started firewalld - dynamic firewall daemon.

Nov  :: CTU1000094955 systemd[]: Stopping firewalld - dynamic firewall daemon...

Nov  :: CTU1000094955 systemd[]: Stopped firewalld - dynamic firewall daemon.

[root@CTU1000094955 ~]# systemctl start firewalld.service

[root@CTU1000094955 ~]# systemctl status firewalld.service

?.firewalld.service - firewalld - dynamic firewall daemon

   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)

   Active: active (running) since Sat -- :: CST; 5s ago

 Main PID:  (firewalld)

   CGroup: /system.slice/firewalld.service

           ?.. /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid

Nov  :: CTU1000094955 systemd[]: Starting firewalld - dynamic firewall daemon...

Nov  :: CTU1000094955 systemd[]: Started firewalld - dynamic firewall daemon.

[root@CTU1000094955 ~]# systemctl list-unit-files |grep firewall

firewalld.service                           disabled

[root@CTU1000094955 ~]# firewall-cmd --permanent --list-port

/tcp /tcp

[root@CTU1000094955 ~]# man firewall-cmd
FIREWALL-CMD()                                                                        firewall-cmd                                                                        FIREWALL-CMD()

NAME

       firewall-cmd - firewalld command line client

SYNOPSIS

       firewall-cmd [OPTIONS...]

DESCRIPTION

       firewall-cmd is the command line client of the firewalld daemon. It provides interface to manage runtime and permanent configuration.

       The runtime configuration in firewalld is separated from the permanent configuration. This means that things can get changed in the runtime or permanent configuration.

OPTIONS

       The following options are supported:

   General Options

       -h, --help

           Prints a short help text and exits.

       -V, --version

           Print the version string of firewalld. This option is not combinable with other options.

       -q, --quiet

           Do not print status messages.

   Status Options

       --state

           Check whether the firewalld daemon is active (i.e. running). Returns an exit code  if it is active, NOT_RUNNING otherwise (see the section called ?.XIT CODES?.. This will

           also print the state to STDOUT.

       --reload

           Reload firewall rules and keep state information. Current permanent configuration will become new runtime configuration, i.e. all runtime only changes done until reload are

           lost with reload if they have not been also in permanent configuration.

       --complete-reload

[root@CTU1000094955 ~]# firewall-cmd --state

running

[root@CTU1000094955 ~]# firewall-cmd --permanent --list-port

/tcp /tcp

[root@CTU1000094955 ~]# firewall-cmd --permanent --remove-port=/tcp

success

[root@CTU1000094955 ~]# firewall-cmd --permanent --list-port

/tcp

[root@CTU1000094955 ~]# firewall-cmd --permanent --zone=public --add-port=/tcp

success

[root@CTU1000094955 ~]# firewall-cmd --permanent --list-port

/tcp /tcp