How do I check if port 3306 is open?

Enter your public IP or hostname into the scanner tool and click Check. A sub-second raw TCP socket handshake will be initiated from our edge server to port 3306 on your target. If the 3-way handshake finishes with SYN-ACK, the port is OPEN. If an RST packet is returned, the host is reachable but the port is CLOSED. If packets time out without response, the port is FILTERED by an ISP or firewall.

Why does port 3306 show as closed or filtered?

If port 3306 reports CLOSED or FILTERED, confirm that: 1) Your service is actively running and bound to 0.0.0.0 (not just localhost/127.0.0.1); 2) Your router has a port forwarding rule directing external port 3306 to your machine's local IP; 3) Your operating system firewall (Windows Defender Firewall, ufw, or iptables) allows incoming connections on port 3306.

PORT 3306 TCP Database High Risk

Port 3306 (MySQL / MariaDB Database) Open Check

Q: What is port 3306 used for?

Port 3306 is the standard TCP port used for MySQL / MariaDB Database. It is commonly used by MySQL Server, MariaDB, Percona Server, phpMyAdmin. Default connection port for MySQL and MariaDB relational database management systems.

Q: Is port 3306 safe to expose to the public internet?

Exposing port 3306 carries elevated security risks (High risk). Exposing MySQL directly to the public internet attracts constant password brute-forcing. Never expose without TLS, strict IP whitelisting, or a VPN tunnel. For remote services, consider placing them behind a secure VPN (such as WireGuard or Tailscale) or restricting inbound access with strict IP firewall rules.

Default connection port for MySQL and MariaDB relational database management systems.

Live Socket Reachability Probe

Pre-configured for Port 3306

Port Scanner

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Target hosts and tested ports will appear here automatically for fast 1-click re-testing.

Auto-prunes oldest probes beyond 10 entries (FIFO)

Port Specifications & Network Behavior

Standard Port Number 3306

Primary Service MySQL / MariaDB Database

Transport Protocol TCP

Traffic Classification Database

Residential ISP Status Typically unrestricted by consumer ISPs

Security Exposure High Exposure discouraged without VPN or firewall protection

Security Advisory: MySQL / MariaDB Database (Port 3306)

Exposing MySQL directly to the public internet attracts constant password brute-forcing. Never expose without TLS, strict IP whitelisting, or a VPN tunnel.

Recommendation: Keep port 3306 closed to WAN traffic. Connect remotely using WireGuard, Tailscale, or an SSH tunnel.

Port Forwarding & Troubleshooting Checklist

If port 3306 returns CLOSED or FILTERED, work through this verified diagnostic checklist:

1 Inspect my.cnf / my.ini and change 'bind-address = 127.0.0.1' to '0.0.0.0'.
2 Ensure database user account has permission to connect from remote hosts ('user'@'%' or specific IP).
3 Verify router and host firewall permit TCP 3306.

Verify Host Is Listening Locally

Windows (PowerShell) netstat -ano | findstr :3306

Linux / macOS (Bash) ss -tulpn | grep :3306