SERVICE_NAME in tnsnames.ora

Hi
We have a 11.2.0.3 RAC database and we are using following tnsnames.ora entry to connect to the database

PROD =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.10.10.1)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.10.10.3)(PORT = 1521))
    (LOAD_BALANCE = yes)
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = prod.dc.net)
      (FAILOVER_MODE =
              (TYPE = SELECT)
              (METHOD = BASIC)
              (RETRIES = 180)
              (DELAY = 5)
      )
    )
  )


Now, when we use the above tnsnames.ora entry, we are able to connect but when we take out "dc.net" from
SERVICE_NAME clause, i.e, we changed the SERVICE_NAME to --> (SERVICE_NAME = prod), we get the following
error

ERROR:
ORA-12514: TNS:listener does not currently know of service requested in connect descriptor