1、配置防火墙，打开3306端口
sudo ufw status
sudo ufw allow 3306
netstat -an | grep 3306
2、此时连接仍然失败，报错
ERROR 1130 (HY000): Host '192.168.116.129' is not allowed to connect to this MySQL server
原因是mysql只允许本主机访问，这时更改配置，进入ubuntu下mysql，输入下面命令
use mysql
select host from user where user = 'root';
update user set host='%' where user = 'root';
flush privileges;
连接成功