mysql cannot connect to remote

MySQL is a commonly used relational database management system, which can interact with data between different servers. However, in actual applications, sometimes there is a problem that MySQL cannot connect to the remote server. This article will cover some common causes and solutions.

1. The reason why Mysql cannot connect to the remote:

1. The port is not open or blocked by the firewall

By default, the port that the MySQL server listens to It is port 3306. If the port is not open or blocked by a firewall, you cannot connect to the MySQL server. You need to ensure that the server port is open or modify the firewall rules.

2. The wrong IP address is bound

If the MySQL server is bound to the wrong IP address, the client cannot connect to the server. You need to confirm whether the IP address monitored by the MySQL server is correct.

3. MySQL does not enable remote connections

By default, the MySQL server does not allow remote connections. If you need remote connection, you need to modify the MySQL configuration file my.cnf or my.ini. There are two ways to allow remote connections. One is to set bind-address to 0.0.0.0 or the server IP address in the configuration file. The other is to add a user that allows remote connections in MySQL and configure the corresponding permissions.

4. Incorrect username and password

If the username and password are incorrect, you cannot connect to the MySQL server. Need to check whether the correct username and password have been entered.

2. Methods to solve the problem that MySQL cannot connect to the remote:

1. Open the MySQL default port

If you find that the MySQL default port (3306) is not open, You need to open it. On Linux systems, you can use the iptables command to open ports. For example, to open port 3306, you can use the following command:

iptables -I INPUT -p tcp --dport 3306 -j ACCEPT

This command will add a rule in the firewall to allow external The host accesses port 3306 of the MySQL server. If MySQL is running on a Windows system, the corresponding port in the Windows firewall needs to be opened.

2. Bind the correct IP address of MySQL

To bind the correct IP address, you need to edit the MySQL configuration file. The configuration file is usually located at /etc/mysql/my.cnf or /etc/my.cnf. In the file, you need to set the value of the bind-address configuration item to the correct IP address of the MySQL server.

bind-address = 127.0.0.1

127.0.0.1 can be replaced with the IP address of the server to allow external hosts to connect to MySQL.

3. Enable MySQL remote connection function

MySQL does not allow remote connections by default and needs to be enabled manually. To enable remote connections, you need to edit the configuration file. In the configuration file, find the bind-address configuration item and set it to 0.0.0.0 or the IP address of the MySQL server. This will allow external hosts to connect to the MySQL server.

4. Check MySQL username and password

If MySQL cannot connect to the remote server, the username or password may be incorrect. You need to make sure that the username and password entered are correct. If you forget your password, you can use the reset password function in MySQL. For specific steps, please refer to the MySQL official documentation.

Summary:

The problem that MySQL cannot connect to the remote server is a common problem, but it is usually caused by errors in the port, IP address, remote connection function, or user name and password. Solutions include opening ports, binding the correct IP address, opening remote connections and checking usernames and passwords. If you encounter the problem of being unable to connect to the remote server, you can solve it according to the above methods.

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