PROBLEM:

While starting the lister , getting below error.

# lsnrctl start LISTENER_TEST

LSNRCTL for Solaris: Version 12.1.0.2.0 – Production on 03-SEP-2018 09:34:26

Copyright (c) 1991, 2017, Oracle. All rights reserved.

TNS-01106: Listener using listener name LISTENER_DBACLASS has already been started

where ( listener.ora)

LISTENER_TEST =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = dbaclasshost)(PORT = 1521))
    )
  )

SID_LIST_LISTENER_TEST =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = DBACLASS)
      (ORACLE_HOME = /oracle/app/oracle/product/12.1.0.2/dbhome_1)
    )
  )

We are trying to start LISTENER_TEST, However, the error we are getting is LISTENER_DBACLASS already started. So how these listeners are related?

SOLUTION:

This error will come, when we are trying to start a listener with a port, which is being used by a different running listener. In simple words,
Two listeners cannot have same port.

Check the port being used by LISTENER_DBACLASS.

# lsnrctl status LISTENER_DBACLASS



LSNRCTL for Solaris: Version 12.1.0.2.0 - Production on 03-SEP-2018 09:34:41

Copyright (c) 1991, 2017, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=DBACLASS)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER_DBACLASS
Version                   TNSLSNR for Solaris: Version 12.1.0.2.0 - Production
Start Date                20-AUG-2018 12:44:00
Uptime                    13 days 20 hr. 50 min. 40 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /oracle/app/oracle/product/12.1.0.2/dbhome_1/network/admin/listener.ora
Listener Log File         /oracle/app/oracle/diag/tnslsnr/dbaclasshost/listener_DBACLASS/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=dbaclasshost)(PORT=1521))) ----------------->>>>>>>>>>>>>> 
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=dbaclasshost)(PORT=5500))(Security=(my_wallet_directory=/oracle/app/oracle/product/12.1.0.2/dbhome_1/ad
RAW))
Services Summary...
Service "DBACLASS" has 1 instance(s).
  Instance "DBACLASS", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

So the listener LISTENER_DBACLSS is using 1521 port. And the listener which we are trying start LISTENER_TEST also contains 1521 port.

So now change the port for LISTENER_TEST and start it.

We have changed from 1521 to 1523 in the listener.ora file

LISTENER_TEST =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = dbaclasshost)(PORT = 1523))
    )
  )

SID_LIST_LISTENER_TEST =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = DBACLASS)
      (ORACLE_HOME = /oracle/app/oracle/product/12.1.0.2/dbhome_1)
    )
  )
  

Start the listener.

# lsnrctl start LISTENER_TEST

LSNRCTL for Solaris: Version 12.1.0.2.0 - Production on 03-SEP-2018 09:35:45

Copyright (c) 1991, 2017, Oracle.  All rights reserved.

Starting /oracle/app/oracle/product/12.1.0.2/dbhome_1/bin/tnslsnr: please wait...

TNSLSNR for Solaris: Version 12.1.0.2.0 - Production
System parameter file is /oracle/app/oracle/product/12.1.0.2/dbhome_1/network/admin/listener.ora
Log messages written to /oracle/app/oracle/diag/tnslsnr/dbaclasshost/listener_test/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=dbaclasshost)(PORT=1523)))

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=dbaclasshost)(PORT=1523)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER_TEST
Version                   TNSLSNR for Solaris: Version 12.1.0.2.0 - Production
Start Date                03-SEP-2018 09:35:45
Uptime                    0 days 0 hr. 0 min. 0 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /oracle/app/oracle/product/12.1.0.2/dbhome_1/network/admin/listener.ora
Listener Log File         /oracle/app/oracle/diag/tnslsnr/dbaclasshost/listener_test/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=dbaclasshost)(PORT=1523)))
Services Summary...
Service "DBACLASS" has 1 instance(s).
  Instance "DBACLASS", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

It worked.