很多人都知道，oracle的监听器一直存在着一个安全隐患，假如不设置安全措施，那么能够访问的用户就可以远程关闭监听器。

相关示例：

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.

正在连接到 (description=(address=(protocol=tcp)(host=172.16.33.11)(port=1521))

(connect_data=(service_name=eygle)))

命令执行成功

大家可以发现，此时缺省的监听器的日志还无法记录操作地址：

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

为了更好的保证监听器的安全，大家最好为监听设置密码：

[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

在我们设置密码后，远程操作将会因缺失密码而出现失败：

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.

正在连接到 (description=(address=(protocol=tcp)(host=172.16.33.11)

(port=1521))(connect_data=(service_name=eygle)))

tns-01169: 监听程序尚未识别口令

注意：此时在服务器端或客户端，都需要我们通过密码来起停监听器：

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参数也是一个重要的安全选项，大家可以在 listener.ora 文件中设置 admin_restrictions_ 为 on，此后所有在运行时对监听器的修改都将会被阻止，所有对监听器的修改都必须通过手工修改listener.ora文件才能顺利完成。

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