Cannot connect remotely to MySQL database located on Plesk for Linux server: Can’t connect to MySQL server on ‘203.0.113.2’ (110)

Symptoms

• Remote connection to a MySQL database located on Plesk for Linux server fails:

  # mysql -ujohndoe -p -P3306 -h 203.0.113.2
  Enter password:
  ERROR 2003 (HY000): Can’t connect to MySQL server on ‘203.0.113.2’ (110)

• Remote connection to the Plesk server on the port 3306 using telnet utility also fails:

  # telnet 203.0.113.2 3306
  Trying 203.0.113.2…
  telnet: connect to address 203.0.113.2: Connection timed out

• Connecting using the desktop client HeidiSQL fails with the error:

  Error code 10060

• In the server shell, connection to the server’s public IP address on the port 3306 works:

  # mysql -ujohndoe -p -P3306 -h 203.0.113.2
  Enter password:
  Welcome to the MariaDB monitor. Commands end with ; or g.
  …

  MariaDB [(none)]>

Cause

Rule for port 3306 is missing on the local firewall or port blocked by the external firewall

Resolution

1. Log in to Plesk

2. Navigate to Tools & Settings > Firewall

3. Disable and enable again Firewall rules

Note: If the above did not help, contact the network administrator or service provider in order to open port 3306.