RAC1 files :

# listener.ora.rac1 Network Configuration File: C:\oracle\product\10.2.0\db_1\network\admin\listener.ora.rac1
# Generated by Oracle configuration tools.

LISTENER_rac1 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = rac1-vip)(PORT = 1521)(IP = FIRST))
      (ADDRESS = (PROTOCOL = TCP)(HOST = rac1)(PORT = 1521)(IP = FIRST))
    )
  )

----------------------------------------------------------------------------------

# tnsnames.ora Network Configuration File: C:\oracle\product\10.2.0\db_1\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.

abc2 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac2-vip)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = abc)
      (INSTANCE_NAME = abc2)
    )
  )

abc1 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac1-vip)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = abc)
      (INSTANCE_NAME = abc1)
    )
  )

abc =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac1-vip)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac2-vip)(PORT = 1521))
    (LOAD_BALANCE = yes)
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = abc)
    )
  )

LISTENERS_abc =
  (ADDRESS_LIST =
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac1-vip)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac2-vip)(PORT = 1521))
  )

TESTRAC =
(DESCRIPTION = 
 (ADDRESS_LIST =
   (LOAD_BALANCE = yes) 
   (ADDRESS = (PROTOCOL = TCP)(HOST = rac1)(PORT = 1521)) 
   (ADDRESS = (PROTOCOL = TCP)(HOST = rac2)(PORT = 1521)) 
 )
 (CONNECT_DATA = 
  (SERVICE_NAME = abc) 
  (failover_mode=(type=select)(method=basic)) 
 ) 
)



----------------------------------------------------------------------------------------



LSNRCTL for 32-bit Windows: Version 10.2.0.5.0 - Production on 08-OCT-2011 07:58:19

Copyright (c) 1991, 2010, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=abc)(INSTANCE_NAME=abc1)))
Services Summary...
Service "+ASM" has 1 instance(s).
  Instance "+asm1", status BLOCKED, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         LOCAL SERVER
Service "+ASM_XPT" has 1 instance(s).
  Instance "+asm1", status BLOCKED, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         LOCAL SERVER
Service "abc" has 2 instance(s).
  Instance "abc1", status READY, has 2 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:3 refused:0 state:ready
         LOCAL SERVER
      "DEDICATED" established:0 refused:0 state:ready
         REMOTE SERVER
         (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=abc)(INSTANCE_NAME=abc1)))
  Instance "abc2", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         REMOTE SERVER
         (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac2-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=abc)(INSTANCE_NAME=abc2)))
Service "abcXDB" has 2 instance(s).
  Instance "abc1", status READY, has 1 handler(s) for this service...
    Handler(s):
      "D000" established:0 refused:0 current:0 max:1002 state:ready
         DISPATCHER <machine: rac1, pid: 2540>
         (ADDRESS=(PROTOCOL=tcp)(HOST=rac1)(PORT=3530))
  Instance "abc2", status READY, has 1 handler(s) for this service...
    Handler(s):
      "D000" established:0 refused:0 current:0 max:1002 state:ready
         DISPATCHER <machine: rac2, pid: 1440>
         (ADDRESS=(PROTOCOL=tcp)(HOST=rac2)(PORT=3630))
Service "abc_XPT" has 2 instance(s).
  Instance "abc1", status READY, has 2 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:3 refused:0 state:ready
         LOCAL SERVER
      "DEDICATED" established:0 refused:0 state:ready
         REMOTE SERVER
         (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=abc)(INSTANCE_NAME=abc1)))
  Instance "abc2", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         REMOTE SERVER
         (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac2-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=abc)(INSTANCE_NAME=abc2)))
The command completed successfully

---------------------------------------------------------------------------


SQL> sho parameter listener

NAME                                 TYPE        VALUE                          
------------------------------------ ----------- ------------------------------ 
local_listener                       string      abc1                       
remote_listener                      string      LISTENERS_abc              

SQL> sho parameter service

NAME                                 TYPE        VALUE                          
------------------------------------ ----------- ------------------------------ 
service_names                        string      abc                        
SQL> spool off;

----------------------------------------------------------------------------------------






RAC2 files :

# listener Network Configuration File: C:\oracle\product\10.2.0\db_1\network\admin\
# Generated by Oracle configuration tools.

LISTENER_rac2 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = rac2-vip)(PORT = 1521)(IP = FIRST))
      (ADDRESS = (PROTOCOL = TCP)(HOST = rac2)(PORT = 1521)(IP = FIRST))
    )
  )

------------------------------------------------------------------------------

# tnsnames.ora Network Configuration File: C:\oracle\product\10.2.0\db_1\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.

abc2 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac2-vip)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = abc)
      (INSTANCE_NAME = abc2)
    )
  )

abc1 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac1-vip)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = abc)
      (INSTANCE_NAME = abc1)
    )
  )

abc =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac1-vip)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac2-vip)(PORT = 1521))
    (LOAD_BALANCE = yes)
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = abc)
    )
  )

LISTENERS_abc =
  (ADDRESS_LIST =
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac1-vip)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac2-vip)(PORT = 1521))
  )

TESTRAC =
(DESCRIPTION = 
 (ADDRESS_LIST =
   (LOAD_BALANCE = yes) 
   (ADDRESS = (PROTOCOL = TCP)(HOST = rac1)(PORT = 1521)) 
   (ADDRESS = (PROTOCOL = TCP)(HOST = rac2)(PORT = 1521)) 
 )
 (CONNECT_DATA = 
  (SERVICE_NAME = abc) 
  (failover_mode=(type=select)(method=basic)) 
 ) 
)

------------------------------------------------------------------------------


LSNRCTL for 32-bit Windows: Version 10.2.0.5.0 - Production on 08-OCT-2011 08:01:04

Copyright (c) 1991, 2010, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac2-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=abc)(INSTANCE_NAME=abc2)))
Services Summary...
Service "+ASM" has 1 instance(s).
  Instance "+asm2", status BLOCKED, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         LOCAL SERVER
Service "+ASM_XPT" has 1 instance(s).
  Instance "+asm2", status BLOCKED, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         LOCAL SERVER
Service "abc" has 2 instance(s).
  Instance "abc1", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:1 refused:0 state:ready
         REMOTE SERVER
         (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=abc)(INSTANCE_NAME=abc1)))
  Instance "abc2", status READY, has 2 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         LOCAL SERVER
      "DEDICATED" established:0 refused:0 state:ready
         REMOTE SERVER
         (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac2-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=abc)(INSTANCE_NAME=abc2)))
Service "abcXDB" has 2 instance(s).
  Instance "abc1", status READY, has 1 handler(s) for this service...
    Handler(s):
      "D000" established:0 refused:0 current:0 max:1002 state:ready
         DISPATCHER <machine: rac1, pid: 2540>
         (ADDRESS=(PROTOCOL=tcp)(HOST=rac1)(PORT=3530))
  Instance "abc2", status READY, has 1 handler(s) for this service...
    Handler(s):
      "D000" established:0 refused:0 current:0 max:1002 state:ready
         DISPATCHER <machine: rac2, pid: 1440>
         (ADDRESS=(PROTOCOL=tcp)(HOST=rac2)(PORT=3630))
Service "abc_XPT" has 2 instance(s).
  Instance "abc1", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:1 refused:0 state:ready
         REMOTE SERVER
         (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=abc)(INSTANCE_NAME=abc1)))
  Instance "abc2", status READY, has 2 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         LOCAL SERVER
      "DEDICATED" established:0 refused:0 state:ready
         REMOTE SERVER
         (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac2-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=abc)(INSTANCE_NAME=abc2)))
The command completed successfully

-------------------------------------------------------------------------------

SQL> sho parameter listener

NAME                                 TYPE        VALUE                          
------------------------------------ ----------- ------------------------------ 
local_listener                       string      abc2                       
remote_listener                      string      LISTENERS_abc              

SQL> sho parameter service

NAME                                 TYPE        VALUE                          
------------------------------------ ----------- ------------------------------ 
service_names                        string      abc                        
SQL> spool off;

----------------------------------------------------------------------------------






Client TNS :

TESTRAC =
(DESCRIPTION = 
 (ADDRESS_LIST =
   (LOAD_BALANCE = yes) 
   (ADDRESS = (PROTOCOL = TCP)(HOST = rac1)(PORT = 1521)) 
   (ADDRESS = (PROTOCOL = TCP)(HOST = rac2)(PORT = 1521)) 
 )
 (CONNECT_DATA = 
  (SERVICE_NAME = abc) 
  (failover_mode=(type=select)(method=basic)) 
 ) 
)