ORA-28547:连接服务器失败，可能是Oracle Net管理错误

原因：PROGRAM和ENVS参数的设置会导致客户端通过SID_NAME来进行连接，由此会引发ORA-28547错误
首先在计算机中找到listener.ora这个文件

打开【listener.ora】文件，去除PROGRAM和ENVS

[oracle@localhost ~]$ cat /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = orcl)
(ORACLE_HOME = /u01/app/oracle/product/11.2.0/dbhome_1)
(PROGRAM = extproc) ##去掉此行
)
)

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.136.211)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
)

记住一定要重启监听器哟