很多人都知道，Oracle的監聽器一直存在著一個安全隱患，假如不設置安全措施，那么能夠訪問的用戶就可以遠程關閉監聽器。

相關示例：

D:>lsnrctl stop eygle

LSNRCTL for 32-bit Windows: Version 10.2.0.3.0 - Production on 28-11月-2007 10:02:40

Copyright (c) 1991, 2006, Oracle. All rights reserved.

正在連接到 (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=172.16.33.11)(PORT=1521))

(CONNECT_DATA=(SERVICE_NAME=eygle)))

命令執行成功

大家可以發現，此時缺省的監聽器的日志還無法記錄操作地址：

No longer listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=172.16.33.11)(PORT=1521)))

28-NOV-2007 09:59:20 * (CONNECT_DATA=(CID=(PROGRAM=)(HOST=)(USER=Administrator))(COMMAND=stop)

(ARGUMENTS=64)(SERVICE=eygle)(VERSION=169870080)) * stop * 0

為了更好的保證監聽器的安全，大家最好為監聽設置密碼：

[oracle@jumper log]$ lsnrctl

LSNRCTL for Linux: Version 9.2.0.4.0 - Production on 28-NOV-2007 10:18:17

Copyright (c) 1991, 2002, Oracle Corporation. All rights reserved.

Welcome to LSNRCTL, type 'help' for information.

LSNRCTL> set current_listener listener

Current Listener is listener

LSNRCTL> change_password

Old password:

New password:

Reenter new password:

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=172.16.33.11)(PORT=1521)))

Password changed for listener

The command completed successfully

LSNRCTL> set password

Password:

The command completed successfully

LSNRCTL> save_config

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=172.16.33.11)(PORT=1521)))

Saved LISTENER configuration parameters.

Listener Parameter File /opt/oracle/product/9.2.0/network/admin/listener.ora

Old Parameter File /opt/oracle/product/9.2.0/network/admin/listener.bak

The command completed successfully

在我們設置密碼后，遠程操作將會因缺失密碼而出現失敗：

D:>lsnrctl stop eygle

LSNRCTL for 32-bit Windows: Version 10.2.0.3.0 - Production on 28-11月-2007 10:22:57

Copyright (c) 1991, 2006, Oracle. All rights reserved.

正在連接到 (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=172.16.33.11)

(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=eygle)))

TNS-01169: 監聽程序尚未識別口令

注意：此時在服務器端或客戶端，都需要我們通過密碼來起停監聽器：

LSNRCTL> set password

Password:

The command completed successfully

LSNRCTL> stop

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=172.16.33.11)(PORT=1521)))

The command completed successfully

LSNRCTL> start

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-NOV-2007 10:22:23

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

另外，ADMIN_RESTRICTIONS參數也是一個重要的安全選項，大家可以在 listener.ora 文件中設置 ADMIN_RESTRICTIONS_ 為 ON，此后所有在運行時對監聽器的修改都將會被阻止，所有對監聽器的修改都必須通過手工修改listener.ora文件才能順利完成。