CentOS 7.0設定防火牆

CentOS 7.0預設使用的是firewall作為防火牆， 使用systemctl來管理服務和程式，包括了service和chkconfig

1、檢視預設防火牆狀態（關閉後顯示not running，開啟後顯示running）

[[email protected] ~]# firewall-cmd --state
not running

2、檢查防火牆的狀態

[[email protected] ~]# systemctl list-unit-files|grep firewalld.service
firewalld.service                             disabled
或者：
[
 
[email protected] ~]# 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)                 --表示防火牆已經關閉
  Docs: man:firewalld(1)

3、開啟防火牆

[[email protected]
 
 ~]#systemctl start firewalld.service       --啟動firewall
[[email protected] ~]# systemctl enable firewalld.service     --開機時啟動firewall
Created symlink from /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service to /usr/lib/systemd/system/firewalld.service.
Created symlink from /etc/systemd/system/multi-user.target.wants/firewalld.service to /usr/lib/systemd/system/firewalld.service. 
 

4、關閉防火牆：

[[email protected] ~]#systemctl stop firewalld.service            --停止firewall
[[email protected] ~]# systemctl disable firewalld.service        --禁止firewall開機啟動
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.

5、重啟防火牆

[[email protected] ~]# systemctl restart firewalld.service

6、檢視防火牆是否開機自啟

[[email protected] ~]# systemctl is-enabled firewalld.service;echo $?
enabled             --自啟
0
或者：
[[email protected] ~]# systemctl is-enabled firewalld.service;echo $?
disabled                --不自啟
1

7、檢視已啟動的服務列表

[[email protected] ~]# systemctl list-unit-files|grep enabled
auditd.service                                      enabled 
[email protected]                                     enabled 
avahi-daemon.service                                enabled 
crond.service                                       enabled 

8、開啟埠

[[email protected] ~]# firewall-cmd --zone=public --add-port=80/tcp --permanent
success
命令含義：
–zone #作用域
–add-port=80/tcp #新增埠，格式為：埠/通訊協議
–permanent #永久生效，沒有此引數重啟後失效

9、檢視已經開放的埠

[[email protected] ~]# firewall-cmd --list-port
80/tcp

10、遮蔽FirewallD服務

[[email protected] ~]#systemctl mask firewalld
還可以通過建立一個firewall.service到/dev/null的符號連線來遮蔽防火牆服務。

11、反遮蔽FirewallD服務

[[email protected] ~]#systemctl unmask firewalld
這是反遮蔽FirewallD服務，它會移除遮蔽FirewallD服務時建立的符號連結，故能重新啟用服務。

12、檢查是否已安裝防火牆

[[email protected] ~]#yum install firewalld firewall-config

13、下面說下CentOS7和6的預設防火牆的區別

vi /etc/sysconfig/iptables 
增加規則
-A INPUT -m state --state NEW -m tcp -p tcp --dport 3306 -j ACCEPT
儲存退出後
systemctl restart iptables.service #重啟防火牆使配置生效
systemctl enable iptables.service #設定防火牆開機啟動

14、最後重啟系統使設定生效即可

systemctl start iptables.service #開啟防火牆
systemctl stop iptables.service #關閉防火牆