问题描述；
SUSE10sp2下安装Oracle11g客户端，新建aipcti用户，tnsping vsm（vsm为客户端下服务名）失败，报错：
TNS-03505: Failed to resolve name ，Used parameter files:
/opt/oracle/product/11g/db/network/admin/sqlnet.ora。
而在oracle用户下直接执行此命令则没有问题。
问题处理：
1，使用aipcti用户直接tnsping +数据库IP则没有问题，但显示是通过
Used EZCONNECT adapter to resolve the alias 来解析的。
2，打开客户端下sqlnet.ora,里面有通过客户端访问数据库服务器顺序。可以看到该文件中访问顺序是先访问tnsnames,如果该文件下没有相关内容或访问失败，再通过EZCONNECT访问。
oracle@urp1vsmdb2:/opt/oracle/product/11g/db/network/admin> more sqlnet.ora
# sqlnet.ora Network Configuration File: /opt/oracle/product/11g/db/network/admin/sqlnet.ora
# Generated by Oracle configuration tools.
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
3，显示tnsname.ora的权限：
oracle@urp1vsmdb2:/opt/oracle/product/11g/db/network/admin> ll -al tnsnames.ora
-rw-r----- 1 oracle oinstall 493 2011-09-23 16:09 tnsnames.ora
发现aipcti用户对该文件没有执行权限导致访问失败。
修改tnsnames.ora权限
oracle@urp1vsmdb2:/opt/oracle/product/11g/db/network/admin> chmod 644 tnsnames.ora
oracle@urp1vsmdb2:/opt/oracle/product/11g/db/network/admin> ls -al tnsnames.ora
-rw-r--r-- 1 oracle oinstall 493 2011-09-23 16:09 tnsnames.ora
4，修改后再次在aipcti下执行已经可以正常tnsping 客户端
tnsping vsm
TNS Ping Utility for Linux: Version 11.1.0.7.0 - Production on 26-9?? -2011 14:38:04
Copyright (c) 1997, 2008, Oracle. All rights reserved.
Used parameter files:
/opt/oracle/product/11g/db/network/admin/sqlnet.ora
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 10.110.153.64)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = uivr)))
OK (0 msec)
以下为两种方式下输出结果对比：
1，aipcti用户下使用tnsping+数据库IP
tnsping 10.110.153.64
TNS Ping Utility for Linux: Version 11.1.0.7.0 - Production on 26-9?? -2011 14:05:27
Copyright (c) 1997, 2008, Oracle. All rights reserved.
Used parameter files:
/opt/oracle/product/11g/db/network/admin/sqlnet.ora
Used EZCONNECT adapter to resolve the alias
Attempting to contact (DESCRIPTION=(CONNECT_DATA=(SERVICE_NAME=))(ADDRESS=(PROTOCOL=TCP)(HOST=10.110.153.64)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)
(HOST=10.110.153.64)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=10.110.153.64)(PORT=1521)))
OK (0 msec)
2，aipcti用户下使用tnsping+服务名，正常的：
oracle@urp1vsmdb2:/opt/oracle/product/11g/db/network/admin> tnsping vsm
TNS Ping Utility for Linux: Version 11.1.0.7.0 - Production on 26-SEP-2011 14:28:37
Copyright (c) 1997, 2008, Oracle. All rights reserved.
Used parameter files:
/opt/oracle/product/11g/db/network/admin/sqlnet.ora
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 10.110.153.64)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = uivr)))
OK (10 msec)