Linux 开启mysql远程访问

第一步: 激活网络设置
你需要编辑mysql配置文件my.cnf.
通常状况，my.cnf放置于在以下目录：
/etc/mysql/my.cnf (Debian linux)
/etc/my.cnf （Red Hat Linux/Fedora Linux)
/var/db/mysql/my.cnf (FreeBSD)
然后用vi编辑my.cnf，修改内容从以下行：
[mysqld]
你所需要:
1. 确保skip-networking被删除或者屏蔽，否则不支持TCP/IP 访问
2. 增加行bind-address = ip，替代ip为你的服务器地址
修改后，配置为：
[mysqld]
user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
language = /usr/share/mysql/English
bind-address = 65.55.55.2
# skip-networking
....
..
保存并关闭配置文件
重启mysql服务器:# /etc/init.d/mysql restart

第二步: 授权
方法一：
例如，你想myuser使用mypassword从任何主机连接到mysql服务器的话。
GRANT ALL PRIVILEGES ON *.* TO myuser@'%'  IDENTIFIED BY 'mypassword'  WITH GRANT OPTION;
FLUSH   PRIVILEGES;
如果你想允许用户myuser从ip为192.168.1.6的主机连接到mysql服务器，并使用mypassword作为密码
GRANT ALL PRIVILEGES ON *.* TO 'myuser'@'192.168.1.3'   IDENTIFIED BY 'mypassword'  WITH GRANT OPTION;
FLUSH   PRIVILEGES;
#################################
开启Mysql数据库的远程连接权限：
grant all privileges on *.* to 'root' @'%' identified by 'wrx123';
flush privileges;

方法二：
use mysql;
update user set host = '%' where user = '用户名'; （如果写成 host=localhost 那此用户就不具有远程访问权限）
FLUSH PRIVILEGES;

第三步:  配置防火墙
如果系统装有防火墙iptables,得设置下
修改防火墙配置文件：
vi /etc/sysconfig/iptables
增加下面一行：
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 3306 -j ACCEPT
如果想开通21等端口，只需要将3306换成21等要开放的端口就可以了。
附：iptables
==============================================
# Firewall configuration written by system-config-securitylevel
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp –icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p 50 -j ACCEPT
-A RH-Firewall-1-INPUT -p 51 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp –dport 5353 -d 224.0.0.251 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m udp –dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state ESTABLISHED,RELATED -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 21 -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 3306 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT –reject-with icmp-host-prohibited
COMMIT

================================================
配置后，重新启动 iptable

service iptables restart

这时就可以从外网访问Mysql了。
第四步 测试
From remote system type command:
$ mysql -u webadmin –h ip –p