今天在看关于oracle网络问题的知识，做实验时遇到了以下问题，最终找到了问题所在。
服务器端：oracle11.2.0.3.0
Red Hat Enterprise Linux Server release 5.8 (Tikanga)
监听状态
[oracle@oracle11admin]$ lsnrctl status
LSNRCTL for Linux: Version 11.2.0.3.0 - Production on 22-JAN- 20:26:47
Copyright (c) 1991, , Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=oracle11)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.3.0 - Production
Start Date 22-JAN- 20:05:28
Uptime 0 days 0 hr. 21 min. 20 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/11.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/diag/tnslsnr/o
