我用阿里云服务在终端使用命令：mysql -u eyed -h ed2017.mysql.rds.aliyuncs.com -p（地址为内网地址，且已经在白名单添加上了ecs的地址）报错：
ERROR 2003 (HY000): Can't connect to MySQL server on 'ed2017.mysql.rds.aliyuncs.com' (110)
然后我又ping了地址结果也ping不通
命令：telnet ed2017.mysql.rds.aliyuncs.com
反馈内容：
Trying 100.115.78.86...
telnet: connect to address 100.115.78.86: Connection timed out

命令：ping ed2017.mysql.rds.aliyuncs.com
反馈内容：
PING ed2017.mysql.rds.aliyuncs.com (100.115.78.86) 56(84) bytes of data.
^C
--- ed2017.mysql.rds.aliyuncs.com ping statistics ---
144 packets transmitted, 0 received, 100% packet loss, time 142999ms