634.Your database instance is running. You are not able to access Oracle Enterprise Manager Database
Control because the listener is not started.
Which tool or utility would you use to start the listener?
A. Oracle Net Manager
B. Listener Control utility
C. Database Configuration Assistant
D. Oracle Net Configuration Assistant
Answer: B
答案解析：
参考：http://blog.csdn.net/rlhua/article/details/12612249
启动监听使用lsnrctl start就可以了
如下：
oracle@rtest ~]$ lsnrctl start
LSNRCTL for Linux: Version 11.2.0.3.0 - Production on 10-OCT-2013 15:57:37
Copyright (c) 1991, 2011, Oracle. All rights reserved.
Starting /u01/app/oracle/product/11.2.0/dbhome_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 11.2.0.3.0 - Production
System parameter file is /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/diag/tnslsnr/rtest/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rtest.localdomain)(PORT=1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rtest.localdomain)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.3.0 - Production
Start Date 10-OCT-2013 15:57:37
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/diag/tnslsnr/rtest/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rtest.localdomain)(PORT=1521)))
The listener supports no services
The command completed successfully
使用监听程序控制实用程序可控制监听程序。使用lsnrctl，可以：
• 启动监听程序
• 停止监听程序
• 检查监听程序的状态
• 根据配置文件参数重新初始化监听程序
• 动态配置多个监听程序
• 更改监听程序口令
该实用程序的基本命令语法为：
LSNRCTL> command [listener_name]
发出lsnrctl命令时，如果没有指定其它监听程序名称或执行SET CURRENT_LISTENER命令，此命令将作用于默认的监听程序（名为LISTENER）。如果监听程序名为LISTENER，则可省略listener_name参数。