MySQL Port Numbers
October 26, 2023
MySQL, one of the world's most popular open-source relational database management systems, communicates over a network using a standardized port. If you're configuring MySQL, setting up firewall rules, or debugging network-related issues, it's essential to understand which ports MySQL uses. In this guide, we'll dive into the default MySQL port number and discuss related port considerations.
Default MySQL Port
By default, MySQL uses port
3306 for client-server communication. When you install MySQL without any specific configurations regarding its port number, clients will try to connect to the server on port 3306.
Secure Socket Layer (SSL)
MySQL can also use SSL for encrypted connections. When you configure MySQL to use SSL, it still uses port
3306 by default. The port number doesn't change; instead, the data transmitted over the port is encrypted.
Changing the Default Port
While the default port is
3306, you can configure MySQL to listen on a different port. To do this:
- Open the MySQL configuration file, typically named
- Locate the
portdirective under the
- Change the port value (e.g., to
- Save the file and restart the MySQL server.
Why Change the Default Port?
- Security Through Obscurity: While not a replacement for proper security measures, changing the default port can prevent automated scans from identifying an active MySQL service easily.
- Running Multiple Instances: If you're running multiple MySQL server instances on the same machine, each must have a unique port.
- Port Conflicts: Another application may already be using port
3306, necessitating a change.
Other Relevant Ports
- MySQLX Plugin: If you use the X Plugin for MySQL, it listens for connections on port
- Cluster & Replication: MySQL Cluster and replication setups might use other ports for communication between nodes or between master and slave instances. Ensure you review the specific documentation for your setup.
Checking the Active MySQL Port
If you need to confirm which port your MySQL server is listening on:
From the MySQL prompt:
From the command line, using
If you're running a firewall (e.g.,
ufw), ensure that you allow connections to the MySQL port. For example, with
3306 with your configured port if different.
Understanding MySQL's port numbers and their configurations is essential for proper setup, maintenance, and security of your MySQL environment. Always ensure that any opened port is secured and monitored, irrespective of its number. Remember, while changing the default port can be part of your security strategy, it should never be the only strategy.
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