CentOS防火墙无法启动，在线服务器都需要开启防火墙服务，这是linux系统安全防护最直接有效方式。
1、如果出现
service iptables start
service iptables restart
无法启动/重启防火墙时。
2、最佳的方法是修改配置文件
vi /etc/sysconfig/iptables
-
# Firewall configuration written by system-config-firewall
-
# Manual customization of this file is not recommended.
-
*filter
-
:INPUT ACCEPT [0:0]
-
:FORWARD ACCEPT [0:0]
-
:OUTPUT ACCEPT [0:0]
-
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-
-A INPUT -p icmp -j ACCEPT
-
-A INPUT -i lo -j ACCEPT
-
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
-
COMMIT
然后再启动防火墙
service iptables start
查看防火墙服务
service iptables status
3、如果需要开启例外端口则，增加如下配置：
vi /etc/sysconfig/iptables
-
# Firewall configuration written by system-config-firewall
-
# Manual customization of this file is not recommended.
-
*filter
-
:INPUT ACCEPT [0:0]
-
:FORWARD ACCEPT [0:0]
-
:OUTPUT ACCEPT [0:0]
-
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-
-A INPUT -p icmp -j ACCEPT
-
-A INPUT -i lo -j ACCEPT
-
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-
-A INPUT -m state --state NEW -m tcp -p tcp --dport 3306 -j ACCEPT
-
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
-
COMMIT
如上，增加了3306服务端口
如果需要关闭防火墙自动启动则
查看状态
chkconfig --list iptables
关闭自动启动
chkconfig iptables off
chkconfig --list iptables
(责任编辑：IT) |
