監聽器也有安全？Sure！在缺省的情況下，任意用戶不需要使用任何密碼即通過lsnrctl 工具對Oracle Listener進行操作或關閉，從而造成任意新的會話都將無法建立連接。在Oracle 9i 中Oracle監聽器允許任何一個人利用lsnrctl從遠程發起對監聽器的管理。也容易導致數據庫受到損壞。
1. 未設定密碼情形下停止監聽
[oracle@test ~]$ lsnrctl stop listener_demo92 -->停止監聽，可以看出不需要任何密碼即可停止
LSNRCTL for Linux: Version 9.2.0.8.0 - Production on 26-JUN-2011 08:22:26
Copyright (c) 1991, 2006, Oracle Corporation. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=test)(PORT=1521)))
The command completed successfully
2. 重新啟動監聽並設置密碼
[oracle@test ~]$ lsnrctl
LSNRCTL for Linux: Version 9.2.0.8.0 - Production on 26-JUN-2011 08:24:09
Copyright (c) 1991, 2006, Oracle Corporation. All rights reserved.
Welcome to LSNRCTL, type "help" for information.
LSNRCTL> set current_listener listener_demo92 -->設置當前監聽器
Current Listener is listener_demo92
LSNRCTL> start -->啟動過程也不需要任何密碼,啟動的詳細信息省略
LSNRCTL> change_password -->使用change_password來設置密碼
Old password:
New password:
Reenter new password:
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=test)(PORT=1521)))
Password changed for listener_demo92
The command completed successfully
LSNRCTL> save_config -->注意此處的save_config失敗
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=test)(PORT=1521)))
TNS-01169: The listener has not recognized the password
LSNRCTL> set password -->輸入新設定的密碼驗證
Password:
The command completed successfully
LSNRCTL> save_config -->再次save_config成功
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=test)(PORT=1521)))
Saved listener_demo92 configuration parameters.
Listener Parameter File /oracle/92/network/admin/listener.ora
Old Parameter File /oracle/92/network/admin/listener.bak
The command completed successfully
-->增加密碼之後可以看到listener.ora文件中有一條新增的記錄，即密碼選項(注：盡管使用了密碼管理方式,仍然可以無需密碼啟動監聽)
[oracle@test admin]$ more listener.ora
#----ADDED BY TNSLSNR 26-JUN-2011 05:12:48---
PASSWORDS_listener_demo92 =
#--------------------------------------------
3. 嘗試未使用密碼的情況下停止監聽
[oracle@test ~]$ lsnrctl stop listener_demo92
LSNRCTL for Linux: Version 9.2.0.8.0 - Production on 26-JUN-2011 06:09:51
Copyright (c) 1991, 2006, Oracle Corporation. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=test)(PORT=1521)))
TNS-01169: The listener has not recognized the password -->收到錯誤信息，需要使用密碼認證
4. 使用密碼來停止監聽
[oracle@test ~]$ lsnrctl LSNRCTL> set current_listener listener_demo92 Current Listener is listener_demo92 LSNRCTL> stop Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=test)(PORT=1521))) TNS-01169: The listener has not recognized the password LSNRCTL> set password Password: The command completed successfully LSNRCTL> stop Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=test)(PORT=1521))) The command completed successfully LSNRCTL> status Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=test)(PORT=1521))) TNS-12541: TNS:no listener TNS-12560: TNS:protocol adapter error TNS-00511: No listener Linux Error: 111: Connection refused Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC))) TNS-12541: TNS:no listener TNS-12560: TNS:protocol adapter error TNS-00511: No listener Linux Error: 2: No such file or directory
5. save_config失敗的問題
-->在 Oracle 9i中，使用save_config命令將會失敗
LSNRCTL> save_config
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=<hostname>)(PORT=<port>)))
TNS-01169: The listener has not recognized the password
-->應該先使用set password之後再save_config，則保存配置成功。
LSNRCTL> set password
Password: <the password you chose>
The command completed successfully
/*在Oracle 10g 中不會出現類似的問題，因為在10g中可以使用基於操作系統驗證方式。listener將檢測到如果用戶屬於dba組的成員，
將會被授予改變密碼，保存配置以及停止監聽等權限。 */
6. 配置listener.ora中ADMIN_RESTRICTIONS參數
參數作用：
當在listener.ora文件中設置了ADMIN_RESTRICTIONS參數後，在監聽器運行時，不允許執行任何管理命令，同時set命令將不可用
，不論是在服務器本地還是從遠程執行都不行。此時對於監聽的設置僅僅通過手工修改listener.ora文件，要使修改生效，只能
使用lsnrctl reload命令或lsnrctl stop/start命令重新載入一次監聽器配置信息。
修改方法：
在listener.ora文件中手動加入下面這樣一行
ADMIN_RESTRICTIONS_<監聽器名> = ON
下面是其它網友的補充：
LSNRCTL> change_password
Old password:
New password:
Reenter new password:
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=ecp-uc-db1)(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=ecp-uc-db1)(PORT=1521)))
Saved LISTENER configuration parameters.
Listener Parameter File /opt/oracle/product/10.2.0/db_1/network/admin/listener.ora
Old Parameter File /opt/oracle/product/10.2.0/db_1/network/admin/listener.bak
The command completed successfully
[oracle@ecp-uc-db1 admin]$ cat listener.ora
#—-ADDED BY TNSLSNR 10-JUN-2011 18:13:24—
PASSWORDS_LISTENER = 6D7AA003392C436A
#——————————————–
note：10g數據庫上需要上添加（重啟監聽）
LOCAL_OS_AUTHENTICATION_LISTENER = OFF
1、添加LOCAL_OS_AUTHENTICATION_LISTENER = OFF之前
Security ON: Password or Local OS Authentication
2、添加LOCAL_OS_AUTHENTICATION_LISTENER = OFF之後
Security ON: Password
LSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=ecp-uc-db1)(PORT=1521)))
TNS-01169: The listener has not recognized the password
LSNRCTL> stop
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=ecp-uc-db1)(PORT=1521)))
TNS-01169: The listener has not recognized the password
LSNRCTL> set password 123456
The command completed successfully
LSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=ecp-uc-db1)(PORT=1521)))
STATUS of the LISTENER
————————
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.4.0 – Production
Start Date 10-JUN-2011 18:15:49
Uptime 0 days 0 hr. 1 min. 16 sec
Trace Level off
Security ON: Password
SNMP OFF
Listener Parameter File /opt/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /opt/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary…
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=ECP-UC-DB1)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC0)))
Services Summary…
Service “PLSExtProc” has 1 instance(s).
Instance “PLSExtProc”, status UNKNOWN, has 1 handler(s) for this service…
Service “ecp” has 1 instance(s).
Instance “ecp”, status READY, has 1 handler(s) for this service…
Service “ecpXDB” has 1 instance(s).
Instance “ecp”, status READY, has 1 handler(s) for this service…
Service “ecp_XPT” has 1 instance(s).
Instance “ecp”, status READY, has 1 handler(s) for this service…
The command completed successfully
