An example of ORA-01034 Fault Handling reported by remote connection through monitoring

The error is as follows:
SQL> conn system/test @ test
ERROR:
A ORA-01034: Oracle not available
ORA-27101: shared memory realm does not exist
Linux Error: 2: No such file or directory

1. Check the environment variables and check whether the monitoring status and instance status are normal.
2. tnsping ZSK is also available

C: \> tnsping ZSK

TNS Ping Utility for 64-bit Windows: Version 10.2.0.4.0-Production on 10-FEB-2012 22:51:55

Copyright (c) 1997,200 7, Oracle. All rights reserved.

Used parameter files:
C: \ oracle \ product \ 10.2.0 \ db_1 \ network \ admin \ sqlnet. ora

Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP) (HOST = 192.168.1.1) (PORT = 12521) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = test )))
OK (20 msec)

C: \>

SQL> alter system set local_listener = '(ADDRESS = (PROTOCOL = TCP) (HOST = 134.224.55.118) (PORT = 12521) (SID = ZSK ))';
System altered.

SQL> alter system register;
System altered.

SQL> exit

Test the connection again on the client:
C: \> sqlplus system/test @ test

SQL * Plus: Release 10.2.0.4.0-Production on Fri Feb 10 22:54:49 2012

Copyright (c) 1982,200 7, Oracle. All Rights Reserved.

Connected:
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0-64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL>