环境：在VirtualBox中安装了Ubuntu虚拟机，网络使用了NAT模式，开启了端口转发。
局域网内其他计算机访问虚拟机中的MySQL Server出现两个问题：
Lost connection to MySQL server at 'reading initial communication packet, system error: 0
以及
host is not allowed to connect mysql
1.解决Lost connection to MySQL server at 'reading initial communication packet, system error: 0
修改/etc/mysql/my.cnf
注释#bind-address = 127.0.0.1
在[mysqld]中加入skip-name-resolve
2.解决host is not allowed to connect mysql
进入mysql库：
grant all privileges on *.* to 'root'@'%' identified by 'YourPassword' with grant option;