ORA-12542: TNS:address already in use

solution

D:\oracle\product\10.2.0\db_1\network\admin\listener.ora

INBOUND_CONNECT_TIMEOUT_LISTENER = 0

SID_LIST_LISTENER =

   (SID_LIST =

      (SID_DESC =

      (SID_NAME = PLSExtProc)

      (ORACLE_HOME = D:\oracle\product\10.2.0\db_1)

      (PROGRAM = extproc)

   )

 )

LOG_DIRECTORY_LISTENER = G:\Listener_Trace

LISTENER =

   (DESCRIPTION_LIST =

     (DESCRIPTION =

       (ADDRESS = (PROTOCOL = TCP)(HOST = newpass)(PORT = 1521))

       (ADDRESS = (PROTOCOL = TCP)(HOST = newpass)(PORT = 1523))

     )

   )

And on client side, map net service names to recently added listener protocol address. i.e. 1523, as below:

NEWPASS_29 =

  (DESCRIPTION =

    (ADDRESS_LIST =

      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.6)(PORT = 1521))

      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.6)(PORT = 1523))

   )

  (CONNECT_DATA =

    (SERVER = DEDICATED)

    (SERVICE_NAME = NEWPASS) 

  )

)

after made above changes to listener.ora and tnsnames.ora, TNSPING was successful and able to create DB-link.

You may face mentioned error in following cases:

• New installation
• listener.ora file has been edited manually since the last listener restart
• TCP port number is duplicated across the list of ADDRESS configurations in the listener.ora file.