[<< wikibooks] RAC Attack - Oracle Cluster Database at Home/Install Instant Client
In order to test failover it would be best to connect from a client outside the cluster, so we'll start by downloading and installing Oracle's Basic Instant Client (English-only) and the Instant Client SQLPlus package.

Login to the node collabn1 as user oracle and open a connection to the database as SYSDBA and unlock the SH user account.  Also grant DBA access.
  
 SQL> alter user sh identified by sh account unlock;
  
 User altered.
  
 SQL> grant dba to sh;
  
 Grant succeeded.

Download Oracle's Basic (English-only) Instant Client and Oracle's Instant Client SQLPlus package.  The lab instructor may have made them available, or they can also be downloaded from Oracle's website here:

http://www.oracle.com/technetwork/topics/winsoft-085727.html

The two files you need are:
instantclient-basiclite-*.zip
instantclient-sqlplus-*.zip
Each archive contains a folder named "instantclient_11_2".  Extract this folder (from both archives) into C:\.  (In Explorer you can drag-and-drop or you can choose "Extract All" from the File menu.)

Edit c:\windows\system32\drivers\etc\hosts and add IP addresses for the RAC nodes.

192.168.78.250	collab-scan.vm.ardentperf.com collab-scan
192.168.78.61	collabn1-vip.vm.ardentperf.com collabn1-vip
192.168.78.62	collabn2-vip.vm.ardentperf.com collabn2-vip
192.168.78.51	collabn1.vm.ardentperf.com collabn1
192.168.78.52	collabn2.vm.ardentperf.com collabn2

Test your Instant Client installation by connecting to the database.

 C:\instantclient_11_2> sqlplus sh/sh@//collab-scan/RAC.vm.ardentperf.com

Create a TNSNAMES files and copy the RAC, RAC1 and RAC2 entries from either cluster database node.

 C:\instantclient_11_2> notepad C:\instantclient_11_2\tnsnames.ora
  
 RAC =
   (DESCRIPTION =
     (ADDRESS = (PROTOCOL = TCP)(HOST = collab-scan)(PORT = 1521))
     (CONNECT_DATA =
       (SERVER = DEDICATED)
       (SERVICE_NAME = RAC.vm.ardentperf.com)
     )
   )
  
 RAC2 =
   (DESCRIPTION =
     (ADDRESS = (PROTOCOL = TCP)(HOST = collabn-scan)(PORT = 1521))
     (CONNECT_DATA =
       (SERVER = DEDICATED)
       (SERVICE_NAME = RAC.vm.ardentperf.com)
       (INSTANCE_NAME = RAC2)
     )
   )
  
 RAC1 =
   (DESCRIPTION =
     (ADDRESS = (PROTOCOL = TCP)(HOST = collabn-scan)(PORT = 1521))
     (CONNECT_DATA =
       (SERVER = DEDICATED)
       (SERVICE_NAME = RAC.vm.ardentperf.com)
       (INSTANCE_NAME = RAC1)
     )
   )

Test your TNSNAMES by setting the TNS_ADMIN environment variable and running SQLPLUS.

 C:\instantclient_11_2>set TNS_ADMIN=c:\instantclient_11_2
 C:\instantclient_11_2>sqlplus sh/sh@RAC