ORA-12545: Connect failed because target host or object does not exist

 

Hi,

We are using Oracle 11g (Version 11.1.0.7) in AIX 6.1 platform.

Oracle 11g running in RAC mode.

While users connecting to the database, sometimes they are able to connect and sometimes they are getting connections (Error Message and my tnsnames entry are given below).

My question - Is there any parameter need to be changed in database? OR in front end application connection string?

TAF Connection String:

TEST_TAF =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = xx.xxx.xxx.xxx)(PORT = xxxx))
    (ADDRESS = (PROTOCOL = TCP)(HOST = xx.xxx.xxx.xxx)(PORT = xxxx))
    (LOAD_BALANCE = yes)
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = ORADB1)
      (FAILOVER_MODE =