How to Change MySQL Default Port 3306 and secure mysql with mysql_secure_installation

Stop MySQL Service

Change port in MySQL Configuration File

Restart MySQL Service

Run Security Script (mysql_secure_installation)

Change the password for root 

Remove anonymous users

Disallow root login remotely

Remove test database and access to it

Reload privilege tables now

Login to MySQL Shell with New Password


Step 1 - Stop MySQL Service

For CentOS

[root@DBA-Master ~]# service mysqld stop

For Ubuntu

[root@DBA-Master ~]# service mysql stop

Step 2 - Change Port in MySQL Configuration File

For CentOS

[root@DBA-Master ~]#  vi /etc/my.cnf

[mysqld]


port= 4545

datadir= /home/ist/mysql


save and exit

For Ubuntu

[root@DBA-Master ~]#  vi /etc/mysql/mysql.conf.d/mysqld.cnf


[mysqld]


port=4545

datadir= /home/ist/mysql


save and exit

Step 3 - Restart MySQL Service

For CentOS

[root@DBA-Master ~]# service mysqld start 

For Ubuntu

[root@DBA-Master ~]# service mysql start 

Step 4 - Run Security Script (mysql_secure_installation)

[root@DBA-Master ~]# mysql_secure_installation 


Securing the MySQL server deployment.


Enter password for user root: 


The 'validate_password' plugin is installed on the server.

The subsequent steps will run with the existing configuration

of the plugin.

Using existing password for root.


Estimated strength of the password: 100 

Change the password for root ? ((Press y|Y for Yes, any other key for No) : Y


New password: 


Re-enter new password: 


Estimated strength of the password: 100 

Do you wish to continue with the password provided?(Press y|Y for Yes, any other key for No) : Y

By default, a MySQL installation has an anonymous user,

allowing anyone to log into MySQL without having to have

a user account created for them. This is intended only for

testing, and to make the installation go a bit smoother.

You should remove them before moving into a production

environment.


Remove anonymous users? (Press y|Y for Yes, any other key for No) : Y

Success.


Normally, root should only be allowed to connect from

'localhost'. This ensures that someone cannot guess at

the root password from the network.


Disallow root login remotely? (Press y|Y for Yes, any other key for No) : Y

Success.


By default, MySQL comes with a database named 'test' that

anyone can access. This is also intended only for testing,

and should be removed before moving into a production

environment.


Remove test database and access to it? (Press y|Y for Yes, any other key for No) : Y

 - Dropping test database...

Success.


 - Removing privileges on test database...

Success.


Reloading the privilege tables will ensure that all changes

made so far will take effect immediately.


Reload privilege tables now? (Press y|Y for Yes, any other key for No) : Y

Success.


All done! 


[root@DBA-Master ~]# mysql -uroot -p


Enter password: 

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 13

Server version: 5.7.33 MySQL Community Server (GPL)


Copyright (c) 2000, 2021, Oracle and/or its affiliates.


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> select @@port;

+--------+

| @@port |

+--------+

|   4545 |

+--------+

1 row in set (0.00 sec)


mysql> \q


Here is the video Presentation to Change default Port and secure mysql with mysql_secure_installation in MySQL .