Port 3306: MySQL / MariaDB
Default port of MySQL and MariaDB.
- Port
- 3306
- Protocol
- TCP
- Service
- MySQL / MariaDB
- Exposure
- Do not expose to the internet
What is port 3306 used for?
Database connections.
Is it safe to expose port 3306 to the internet?
Bind to localhost or a private network. If remote access is needed, restrict by IP and use TLS.
If port 3306 seems closed or unreachable
- Check that the MySQL / MariaDB service is running and listening on port 3306, not only on 127.0.0.1.
- Check the firewall on the host itself (Windows Defender Firewall, iptables, nftables, ufw) for a rule that allows TCP 3306.
- If the host is behind a router, confirm the forwarding rule points to the correct internal address and that your internet provider does not use carrier-grade NAT.
- Test from outside your own network. A port can be open locally and blocked at the edge, or the other way round.
Using port 3306 safely
Treat port 3306 as an internal-only service. Reach it through a VPN or an SSH tunnel, restrict it by source address, and keep the software that listens on it patched.
Check whether port 3306 is open on your host
The check connects from our server, so it shows what the internet can reach.
Open the port checker