listener.ora , tnsname.ora sample file

$ORA_HOME/network/admin/listener.ora

LISTENER =

  (DESCRIPTION_LIST =

    (DESCRIPTION =

      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))

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

      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.0.2.15)(PORT = 1521))

    )

  )

SID_LIST_LISTENER =

  (SID_LIST =

   (SID_DESC =

      (SID_NAME = PLSExtProc)

      (ORACLE_HOME = /oracle11/product/11.2.0/dbhome_1)

      (PROGRAM = extproc)

   )

   (SID_DESC =

      (GLOBAL_DBNAME = orcl11)

      (ORACLE_HOME = /oracle11/product/11.2.0/dbhome_1 )

      (SID_NAME = orcl11)

    )

  )

ADR_BASE_LISTENER = /oracle11

$ORA_HOME/network/admin/tnsnames.ora

ORCL11 =

  (DESCRIPTION =

    (ADDRESS_LIST =

      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.0.2.15)(PORT = 1521))

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

    )

    (CONNECT_DATA =

      (SERVER = DEDICATED)

      (SERVICE_NAME = orcl11)

    )

  )

LISTENER_ORCL11 =

 (ADDRESS_LIST =

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

   (ADDRESS = (PROTOCOL = TCP)(HOST = 10.0.2.15)(PORT = 1521))

 )