简单切换root
sudo -i

允许root登陆

echo root:password |sudo chpasswd root
sudo sed -i 's/^.*PermitRootLogin.*/PermitRootLogin yes/g' /etc/ssh/sshd_config;
sudo sed -i 's/^.*PasswordAuthentication.*/PasswordAuthentication yes/g' /etc/ssh/sshd_config;
sudo service sshd restart


关防火墙

#停止firewall
systemctl stop firewalld.service

#禁止firewall开机启动
systemctl disable firewalld.service

#关闭iptables
service iptables stop

#去掉iptables开机启动
chkconfig iptables off


开所有端口

sudo iptables -P INPUT ACCEPT
sudo iptables -P FORWARD ACCEPT
sudo iptables -P OUTPUT ACCEPT
sudo iptables -F