my.cnf中有选项bind-address=127.0.0.1，
是说mysql server监听的是本地发来的请求，如果是任意主机都可以请求，则写为0.0.0.0，但是这样又不太安全。监听某ip，指定此ip地址即可，但是要保证mysql的user中有允许此ip访问，否则不能对数据库操作。

那么是否可以在配置里只规定几个ip呢？
简单直接回答：不可能

请参考：http://dev.mysql.com/doc/refman/5.1/en/server-options.html#option_mysqld_bind-address

The MySQL server listens on a single network socket for TCP/IP
connections. This socket is bound to a single address, but it is
possible for an address to map onto multiple network interfaces. The
default address is 0.0.0.0. To specify an address explicitly, use the
–bind-address=addr option at server startup, where addr is an IPv4
address or a host name. If addr is a host name, the server resolves
the name to an IPv4 address and binds to that address. The server
treats different types of addresses as follows:

If the address is 0.0.0.0, the server accepts TCP/IP connections on
all server host IPv4 interfaces. If the address is a “regular” IPv4
address (such as 127.0.0.1), the server accepts TCP/IP connections
only for that particular IPv4 address.

但是有此需求，就会到访问控制，那么使用防火墙iptables可实现此效果

mysql-server为192.168.1.3，只允许192.168.1.4, 192.168.1.5, 192.168.1.6来访问3306端口

在my.cnf中

bind-address = 0.0.0.0

在访问3306端口的主机中，只允许192.168.1.4-6，其他ip一律DROP掉

/sbin/iptables -A INPUT -p tcp -s 192.168.1.4 --dport 3306 -j ACCEPT
/sbin/iptables -A INPUT -p tcp -s 192.168.1.5 --dport 3306 -j ACCEPT
/sbin/iptables -A INPUT -p tcp -s 192.168.1.6 --dport 3306 -j ACCEPT
/sbin/iptables -A INPUT -p tcp --dport 3306 -j DROP

或

/sbin/iptables -A INPUT -p tcp --dport 3306 ! -s 192.168.1.4 -j DROP
/sbin/iptables -A INPUT -p tcp --dport 3306 ! -s 192.168.1.5 -j DROP
/sbin/iptables -A INPUT -p tcp --dport 3306 ! -s 192.168.1.6 -j DROP

保存防火墙规则

service iptables save

查看INPUT链包含3306的规则

echo -e "target prot opt source destination\n$(iptables -L INPUT -n | grep 3306)"

这样就实现了mysql只允许指定ip访问。