MariaDB: Connecting from LAN on Centos
https://mariadb.com/kb/en/configuring-mariadb-for-remote-client-access/ says : 


  MariaDB only supports one bind-address, but binds to 0.0.0.0, or ::
  (every IP) if the bind-address directive is left out).


I understand that in this case mariadb listens on every IP address of the machine. However even in this case you can filter on hostname at user account level with the user@host syntax.