How to start the Oracle listener and check if it is running on linux?

To start the Oracle listener:

1. Login and go to the Oracle home
   
         cd $ORACLE_HOME or cd oracle_home_directory

2. Run the command: lsnrctl START or $ORACLE_HOME/bin/lsnrctl START

$> lsnrctl STARTLSNRCTL for Linux: Version 12.1.0.2.0 - Production on 13-JUN-2018 11:02:11
Copyright (c) 1991, 2014, Oracle.  All rights reserved.
Starting /12c/app/oracle/product/12.1.0/db_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 12.1.0.2.0 - ProductionSystem parameter file is /12c/app/oracle/product/12.1.0/db_1/network/admin/listener.oraLog messages written to /12c/app/oracle/diag/tnslsnr/myserver_jxs/listener/alert/log.xmlListening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=196.223.1.2)(PORT=1521)))Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=196.223.1.2)(PORT=1521)))STATUS of the LISTENER------------------------Alias                     LISTENERVersion                   TNSLSNR for Linux: Version 12.1.0.2.0 - ProductionStart Date                13-JUN-2018 08:56:06Uptime                    0 days 2 hr. 11 min. 6 secTrace Level               offSecurity                  ON: Local OS AuthenticationSNMP                      OFFListener Parameter File   /12c/app/oracle/product/12.1.0/db_1/network/admin/listener.oraListener Log File         /12c/app/oracle/diag/tnslsnr/myserver_jxs/listener/alert/log.xmlListening Endpoints Summary...  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=myserver_jxs)(PORT=1521)))  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))Services Summary...Service "cs" has 1 instance(s).  Instance "cs", status UNKNOWN, has 1 handler(s) for this service...The command completed successfully

To check if the Oracle listener is running:

1. Repeat step 2 above

$> lsnrctl STARTLSNRCTL for Linux: Version 12.1.0.2.0 - Production on 13-JUN-2018 11:02:11Copyright (c) 1991, 2014, Oracle.  All rights reserved.TNS-01106: Listener using listener name LISTENER has already been started

2. Run: $ORACLE_HOME/bin/tnsping  $ORACLE_SID or tnsping  database_name

$>  tnsping  $ORACLE_SID
TNS Ping Utility for Linux: Version 12.1.0.2.0 - Production on 13-JUN-2018 10:57:52
Copyright (c) 1997, 2014, Oracle.  All rights reserved.
Used parameter files:
/12c/app/oracle/product/12.1.0/db_1/network/admin/sqlnet.ora
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = cs)))
OK (10 msec)

3. Run  lsnrctl STATUS

$> lsnrctl STATUS
LSNRCTL for Linux: Version 12.1.0.2.0 - Production on 13-JUN-2018 11:07:12
Copyright (c) 1991, 2014, Oracle.  All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 12.1.0.2.0 - Production
Start Date                13-JUN-2018 08:56:06
Uptime                    0 days 2 hr. 11 min. 6 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /12c/app/oracle/product/12.1.0/db_1/network/admin/listener.ora
Listener Log File         /12c/app/oracle/diag/tnslsnr/myserver_jxs/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=myserver_jxs)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=myserver_jxs)(PORT=5500))(Security=(my_wallet_directory=/12c/app/oracle/admin/cs/xdb_wallet))(Presentation=HTTP)(Session=RAW))
Services Summary...
Service "cs" has 1 instance(s).
  Instance "cs", status READY, has 1 handler(s) for this service...
Service "csXDB" has 1 instance(s).
  Instance "cs", status READY, has 1 handler(s) for this service...
The command completed successfully

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