在Oracle数据库中，我们可以通过SQLNET.ora文件实现地址访问限制。
在SQLNET.ora文件中设置以下参数可以实现IP访问限制：
tcp.validnode_checking=yes
tcp.invited_nodes=(ip1,ip2……)
tcp.excluded_nodes=(ip1,ip2……)
在未设置这些参数前，测试数据库可以正常访问：
D:\>tnsping eygle
TNS Ping Utility for 32-bit Windows: Version 10.2.0.3.0 – Production on 28-1月 -2008 14:52:52
Copyright (c) 1997, 2006, Oracle. All rights reserved.
已使用的参数文件，:
C:\oracle\10.2.0\network\admin\sqlnet.ora
已使用 TNSNAMES 适配器来解析别名
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 172.16.33.11)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = eygle)))
OK (30 毫秒)
当设置参数之后：
[oracle@jumper admin]$ cat sqlnet.ora
# SQLNET.ORA Network Configuration File: /opt/oracle/product/9.2.0/network/admin/sqlnet.ora
# Generated by Oracle configuration tools.
NAMES.DIRECTORY_PATH= (TNSNAMES, ONAMES, HOSTNAME)
tcp.validnode_checking=yes
tcp.invited_nodes=(172.16.33.11,172.16.34.89)
重新启动监听器使设置生效：
[oracle@jumper admin]$ lsnrctl start
LSNRCTL for Linux: Version 9.2.0.4.0 – Production on 28-JAN-2008 14:42:01
Copyright (c) 1991, 2002, Oracle Corporation. All rights reserved.
Starting /opt/oracle/product/9.2.0/bin/tnslsnr: please wait…
TNSLSNR for Linux: Version 9.2.0.4.0 – Production
System parameter file is /opt/oracle/product/9.2.0/network/admin/listener.ora
Log messages written to /opt/oracle/product/9.2.0/network/log/listener.log
Trace information written to /opt/oracle/product/9.2.0/network/trace/listener.trc
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=172.16.33.11)(PORT=1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=172.16.33.11)(PORT=1521)))
STATUS of the LISTENER
————————
Alias LISTENER
Version TNSLSNR for Linux: Version 9.2.0.4.0 – Production
Start Date 28-JAN-2008 14:42:01
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level support
Security ON
SNMP OFF
Listener Parameter File /opt/oracle/product/9.2.0/network/admin/listener.ora
Listener Log File /opt/oracle/product/9.2.0/network/log/listener.log
Listener Trace File /opt/oracle/product/9.2.0/network/trace/listener.trc
Listening Endpoints Summary…
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=172.16.33.11)(PORT=1521)))
Services Summary…
Service “eygle” has 1 instance(s).
Instance “eygle”, status UNKNOWN, has 1 handler(s) for this service…
Service “julia” has 1 instance(s).
Instance “eygle”, status UNKNOWN, has 1 handler(s) for this service…
The command completed successfully
我们再来看客户端的访问：
D:\>tnsping eygle
TNS Ping Utility for 32-bit Windows: Version 10.2.0.3.0 – Production on 28-1月 -2008 14:53:19
Copyright (c) 1997, 2006, Oracle. All rights reserved.
已使用的参数文件:
C:\oracle\10.2.0\network\admin\sqlnet.ora
已使用 TNSNAMES 适配器来解析别名
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 172.16.33.11)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = eygle)))
TNS-12547: TNS: 丢失连接
需要注意的是一定要将本地地址，或者Cluster群集其他节点的地址都加入到允许列表，否则监听器可能无法启动。
修改参数之后，重启监听器设置即可生效。
通过监听器的限制，通常属于轻量级，比在数据库内部通过触发器进行限制效率要高。