客户端连接不上服务器！

[whuijun]

我的平台是RedHat Advanced server 2.1 + Oracle9.2.0，在配置完数据库之后，在服务器上用sqlplus什么的都可以连接上数据库！而为什么在客户端连接不上数据库呢？
错误信息是：
“正在尝试使用以下用户 ID 连接:system
测试没有成功。
ORA-12560: TNSrotocol adapter error

在输入的字段中可能有错误,
或者服务器连接未就绪。“

用tnsping 的信息是：

“TNS Ping Utility for 32-bit Windows: Version 9.2.0.1.0 - Production on 10-JAN-2003 08:59:31

Copyright (c) 1997 Oracle Corporation. All rights reserved.

Used parameter files:
C:\oracle\ora92\network\admin\sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCPS)(HOST = 140.231.78.3)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = db21)))
TNS-12560: TNSrotocol adapter error”


头一次用Oracle9i，请多指教！多谢！！！

[whuijun]

已经启动了！不行！

[bzszp]

启动监听服务

[bzszp]

启动监听服务

[more_zou]

Cause: A generic protocol adapter error occurred.

Action: Check addresses used for proper protocol specification. Before reporting this error, look at the error stack and check for lower level transport errors.For further details, turn on tracing and re-execute the operation. Turn off tracing when the operation is complete.