How to grant remote access to MySQL for a whole subnet?

105
votes

I can easily grant access to one IP using this code:

$ mysql -u root -p
Enter password:    
mysql> use mysql    
mysql> GRANT ALL ON *.* to root@'192.168.1.4' IDENTIFIED BY 'your-root-password';     
mysql> FLUSH PRIVILEGES;

But i need to allow the whole subnet 192.168.1.* to access the database remotely.

How can i do that?

8
mysqlgrant

8 Answers

133
votes

It looks like you can also use a netmask, e.g.

GRANT ... TO 'user'@'192.168.0.0/255.255.255.0' IDENTIFIED BY ...
109
votes

EDIT: Consider looking at and upvoting Malvineous's answer on this page. Netmasks are a much more elegant solution.

Simply use a percent sign as a wildcard in the IP address.

From http://dev.mysql.com/doc/refman/5.1/en/grant.html

You can specify wildcards in the host name. For example, user_name@'%.example.com' applies to user_name for any host in the example.com domain, and user_name@'192.168.1.%' applies to user_name for any host in the 192.168.1 class C subnet.

31
votes

You would just use '%' as your wildcard like this:

GRANT ALL ON *.* to root@'192.168.1.%' IDENTIFIED BY 'your-root-password';
17
votes
mysql> GRANT ALL ON *.* to root@'192.168.1.%' IDENTIFIED BY 'your-root-password';

The wildcard character is a "%" instead of an "*"

9
votes

Just a note of a peculiarity I faced:
Consider:

db server:  192.168.0.101
web server: 192.168.0.102

If you have a user defined in mysql.user as 'user'@'192.168.0.102' with password1 and another 'user'@'192.168.0.%' with password2,

then,

if you try to connect to the db server from the web server as 'user' with password2,

it will result in an 'Access denied' error because the single IP 'user'@'192.168.0.102' authentication is used over the wildcard 'user'@'192.168.0.%' authentication.

2
votes

Motivated by @Malvineaus answer I tried it myself and noticed that it didn't work for me.

You can specify subnet masks with '192.168.1.%' or '192.168.1.0/255.255.255.0' but the subnet must always be on complete octets. see https://mariadb.com/kb/en/create-user/#host-name-component. As result the functionality between one way of specification and the other is the same.

For example '192.168.1.0/255.255.255.128' will not work as it is not on a complete octet boundary.

1
votes

after you connect server and you want to connect on your host, you should do the steps below:

  1. write mysql to open mysql
  2. write GRANT ALL ON . to root@'write_your_ip_addres' IDENTIFIED BY 'write_password_to_connect';
  3. press control and X to quit from mysql
  4. write nano /etc/mysql/my.cnf
  5. write # before bind-address = 127.0.0.1 in my.cnf folder
  6. #bind-address = 127.0.0.1
  7. save my.cnf folder with control + X
  8. write service mysql restart
  9. you could connect via navicat on your host
1
votes

MySQL 8.0.23 onwards now support CIDR notation also.

So, basically:

-- CIDR Notation
GRANT ... TO 'user'@'192.168.1.0/24' IDENTIFIED BY ...

-- Netmask Notation
GRANT ... TO 'user'@'192.168.1.0/255.255.255.0' IDENTIFIED BY ...