参考自：Deprecation of Listener Password in Oracle Database 11g Release 2 (文档 ID 1328725.1)
适用于：
Oracle Net Services - Version 11.2.0.1 to 11.2.0.3 [Release 11.2]
Information in this document applies to any platform.
checked for currency 8-jul-2013
细节：
在Oracle Database 11gR2中已经废弃了 Listener Password ，这不会导致安全上的损失，因为身份验证通过本地操作系统身份验证的方式来实施。
行动：
When upgrading to Oracle Database 11g Release 2 (Patch Set 11.2.0.3 and later) , follow the steps below to migrate a listener that has a set password:
1. Remove all PASSWORDS_listener_name entries from the listener.ora file.
2. Reload the listener using the following command: lsnrctl reload listener_name
If remote administration of a listener is required, then use one of the following methods to connect to and administer the listener.
? Connect to the host where listener is running using SSH or other secure method, and then perform local administration. Local administration is enforced by the operating system authentication.
? Use Oracle Enterprise Manager to administer the listener. Oracle Enterprise Manager uses HTTPS, which ensures security.
Please note, that this feature will be de-supported in the next major Oracle Database version (currently called 12g) and will then no longer be available.
For more information please refer to the following Oracle Database 11g Release 2 documentation:
Oracle Database Net Services Administrator‘s Guide (html, pdf) - Chapter 9 ‘Configuring and Administering Oracle Net Listener‘
Oracle Database Net Services Reference (html, pdf) - Appendix B ‘Upgrade Considerations for Oracle Net Services‘