在本地（192.168.1.152）部署好mysql环境，授权远程客户机192.168.1.%连接本机的mysql，在iptables防火墙也已开通3306端口。
如下：
mysql> select host,user,password from mysql.user;
+--------------+-----------------+---------------------------------------------------------+
| host | user | password |
+--------------+-----------------+----------------------------------------------------------+
| localhost | root | |
| fdm1 | root | |
| 127.0.0.1 | root | |
| localhost | | |
| fdm1 | | |
| 192.168.1.% | db_hqsb | *DFC9DC16B13651A95ECEC3A26E07D244431B55C9 |
| 192.168.1.% | db_ro_hqsb | *2C0B0DD50595BB40879110437BEEF026D019DFB7 |
| 192.168.1.% | db_jkhwuser | *2C0B0DD50595BB40879110437BEEF026D019DFB7 |
| 192.168.1.25| slave | *EE52B8EACB3CCD13624273AD6B5CDA52B9B53EB7 |
| 192.168.1.% | tech_db_user | *6053E57C7B61043DC2C6B4E3291D5F61CCC23F5C |
| 192.168.1.% | game_db_user| *05EA4D71C9A1273ECF3E24E6323F7175AE45C366 |
| localhost | zabbix | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+---------------+---------------+------------------------------------------------------------+
问题：
在客户机（比如192.168.1.20）上远程连接上面192.168.1.152机器的mysql，连接失败！
[[email protected] ~]# mysql -udb_ro_hqsb -h 192.168.1.152 -pmhxzkhl0802xqsjdb
ERROR 1130 (HY000): Host ‘192.168.1.20‘ is not allowed to connect to this MySQL server
解决：
是由于192.168.1.152的mysql里“host为localhost，user和password为空”这条语句导致的，删除这条即可解决问题！
mysql> delete from mysql.user where host="localhost" and user="";
Query OK, 1 row affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
这样，授权连接的客户机就能成功连接了！
[[email protected] ~]# mysql -uxqsj_db_ro_user -h 192.168.1.152 -pmhxzkhl0802xqsjdb
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 28
Server version: 5.1.73 Source distribution
Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql>