1251 - Client does not support authentication protocol requested by server;consider upgrading MySQL

╰半夏微凉° 2022-01-29 15:45 101阅读 0赞

很多人装了MySQL8.0，然后使用Navicat等客户端登录的时候报了以下错误：![在这里插入图片描述][20190522143545654.png]  
**原因**  
MySQL8.0使用新的密码验证插件caching\_sha2\_password，而MySQL8.0以下的，只要不是太旧的客户端，都是使用mysql\_native\_password验证插件，两个插件不兼容导致了登录异常

[root@mysql8 ~]# mysql
    Welcome to the MySQL monitor.  Commands end with ; or \g.
    Your MySQL connection id is 12
    Server version: 8.0.12 MySQL Community Server - GPL
    
    Copyright (c) 2000, 2018, 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> show variables like 'default_authentication_plugin';
    +-------------------------------+-----------------------+
    | Variable_name                 | Value                 |
    +-------------------------------+-----------------------+
    | default_authentication_plugin | caching_sha2_password |
    +-------------------------------+-----------------------+
    1 row in set (0.02 sec)

**解决**  
将default\_authentication\_plugin设为mysql\_native\_password，并且以mysql\_native\_password插件方式更新一下用户密码，例如我登录使用的用户是root@’%’：  
1.首先在my.cnf加入以下参数，并重启MySQL实例  
default\_authentication\_plugin=mysql\_native\_password  
2.更新登录用户密码  
alter user root@’%’ identified with mysql\_native\_password by ‘sam123’;

通过以上两个步骤，就可以使用Navicat登录了，如果还有问题，排查一下其他原因吧，例如网络、端口、登录权限等。

[20190522143545654.png]: /images/20220129/6b58740948a849c794e2c5f12bdfe9f9.png