Port 3306 (MySQL) — What It Is and How to Use It

Port 3306 is the default port used by the MySQL relational database management system (RDBMS) for client-server communication. It is crucial for applications to connect to and interact with MySQL databases, making it a fundamental port for many web applications and data-driven services.

Last updated: 2026-06-11

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                Port Number
                3306
            

Protocol MySQL

Common Use Cases

Connecting web applications (e.g., WordPress, Joomla, custom PHP/Python apps) to a MySQL database backend.
Database administration tools (e.g., MySQL Workbench, phpMyAdmin) connecting to a MySQL server.
Data replication between MySQL servers.
Business intelligence (BI) tools and reporting software querying MySQL databases.

Interactive Command Builder

Target Host / IP

Operating System

Generated Command

nc -zv example.com 3306

Check if Port 3306 is Open

sudo netstat -tulnp | grep 3306

netstat -ano | findstr :3306

⚠️ Security Note: Leaving port 3306 open to the internet without proper security measures (like strong passwords, IP whitelisting, or VPNs) is a significant security risk, as it exposes your database to potential unauthorized access and attacks. It's highly recommended to restrict access to trusted IP addresses or use SSH tunneling.

Related Ports

Frequently Asked Questions

Is port 3306 dangerous to leave open?

Yes, leaving port 3306 open to the public internet without robust security measures is very dangerous. It can lead to unauthorized access, data breaches, and compromise of your entire system if an attacker gains control of your database.

What service uses port 3306?

Port 3306 is primarily used by the MySQL database server for client-server communication. Other services like MariaDB, a popular fork of MySQL, also use this port by default.