简单来说通过在sqlnet.ora文件中设置如下参数来实现
TCP.VALIDNODE_CHECKING控制是否打开数据库访问控制功能。
TCP.EXCLUDED_NODES 黑名单拒绝访问的IP
TCP.INVITED_NODES 白名单允许访问的IP
举例：
TCP.VALIDNODE_CHECKING = YES
TCP.EXCLUDED_NODES= (138.3.33.33)
TCP.INVITED_NODES=(138.4.44.44, hammer)
被拒绝的提示如： ORA-12537: TNS:connection closed
参考
http://docs.oracle.com/cd/E11882_01/network.112/e41945/profile.htm#NETAG091
Note 462933.1 What is TCP_VALIDNODE_CHECKING and How to Use It
RAC: TCP.VALIDNODE_CHECKING Failing after Listener Reload (文档 ID 2109789.1)
Listener Fails to Start Using TCP.VALIDNODE_CHECKING: TNS-12532 TNS:Invalid Argument (文档 ID 287500.1)