1、firewalld 程序关闭且禁止开机启动
systemctl stop firewalld.service
systemctl disable firewalld.service
2、安装iptables防火墙
yum install iptables-services #安装
vi /etc/sysconfig/iptables #编辑防火墙配置文件
# 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 80 -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
:wq! #保存退出
systemctl restart iptables.service #最后重启防火墙使配置生效
systemctl enable iptables.service #设置防火墙开机启动
3、默认规则:
INPUT链为DROP
FORWARD链为DROP
OUTPUT链为ACCEPT;
1:80、8080端口是对外开放的web服务端口,22122为ssh端口;
2:开放本地127.0.0.1回环接口,放行本地主机内部通信;
3:放行icmp即允许ping通本机;
4:放行RELATED:相关联的连接;放行ESTABLISHED:连接追踪模板当中存在的记录的连接;
5、6:放行dns服务器的地址;
7、8:放行公司的ip访问服务器所有端口;
9-15:放行安骑士的ip和端口
按照上述方法,设置防火墙后,保存规则即可。