配置 iptables 防火墙

# iptables -P INPUT DROP
# iptables -I INPUT -p tcp --dport 22 -j ACCEPT
# iptables -I INPUT -p tcp --dport 80 -j ACCEPT
# iptables -I INPUT -p icmp -j ACCEPT
# service iptables save
# chkconfig iptables on
# chkconfig httpd on
# chkconfig mysqld on