A. ifconfig、nslookup等工具

#ifconfigyum install net-tools#nslookupyum install bind-utils

 B.CentOS 7.0默认使用的是firewall作为防火墙，这里改为iptables防火墙。

1、关闭firewall：

systemctl stop firewalld.service #停止firewallsystemctl disable firewalld.service #禁止firewall开机启动

 

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-prohibitedCOMMIT: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

 

C.关闭SELINUX

sestatus#查看状态vi /etc/selinux/config#SELINUX=enforcing #注释掉#SELINUXTYPE=targeted #注释掉SELINUX=disabled #增加:wq! #保存退出setenforce 0 #使配置立即生效