How to Resolve TNS-12541: TNS:no listener

TNS-12541

Let’s see how we reproduce TNS-12541.

C:\Users\ed>tnsping compdb

TNS Ping Utility for 64-bit Windows: Version 12.1.0.1.0 - Production on 22-JUL-2014 19:20:06

Copyright (c) 1997, 2013, Oracle.  All rights reserved.

Used parameter files:
C:\oracle\app\client\ed\product\12.1.0\client_1\network\admin\sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = primary01)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = compdb)))
TNS-12541: TNS:no listener

Cause

The connection cannot find the listener, it could be not started or at another port, e.g. 1522.

Solution

Check the status and port of LISTENER on server side and start it if necessary.

[oracle@primary01 ~]$ lsnrctl status

LSNRCTL for Linux: Version 12.1.0.1.0 - Production on 22-JUL-2014 19:22:34

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
TNS-12541: TNS:no listener
 TNS-12560: TNS:protocol adapter error
  TNS-00511: No listener
   Linux Error: 2: No such file or directory
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=primary01)(PORT=1521)))
TNS-12541: TNS:no listener
 TNS-12560: TNS:protocol adapter error
  TNS-00511: No listener
   Linux Error: 111: Connection refused

As you can see, the database port is 1521 without questions. But the listener is not started. So let's start it up.

[oracle@primary01 ~]$ lsnrctl start

LSNRCTL for Linux: Version 12.1.0.1.0 - Production on 22-JUL-2014 19:23:59

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Starting /u01/app/oracle/product/12.1.0/dbhome_1/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 12.1.0.1.0 - Production
System parameter file is /u01/app/oracle/product/12.1.0/dbhome_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/diag/tnslsnr/primary01/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=primary01)(PORT=1521)))

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 12.1.0.1.0 - Production
Start Date                22-JUL-2014 19:23:59
Uptime                    0 days 0 hr. 0 min. 2 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/oracle/product/12.1.0/dbhome_1/network/admin/listener.ora
Listener Log File         /u01/app/oracle/diag/tnslsnr/primary01/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=primary01)(PORT=1521)))
The listener supports no services
The command completed successfully

For more testing skills, you may check Oracle 18c Net Services Administrator's Guide: 15 Testing Connections.

8 thoughts on “How to Resolve TNS-12541: TNS:no listener”

  1. Hello Ed,

    Used three of your posts related to listener and TNS setup, they did the trick, all of my issues are resolved. I’ve worked with Oracle since the 1980s and this has always been a hit and miss subject for me, but you have provided an excellent web tech information resource. Well done!!

  2. Hi Ed,

    I have the same issue,I did start the listener but still it doesn’t work.

    LSNRCTL for Linux: Version 12.2.0.1.0 – Production on 14-MAY-2020 10:21:14

    Copyright (c) 1991, 2016, Oracle. All rights reserved.

    Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.1.102)(PORT=1539)))
    STATUS of the LISTENER
    ————————
    Alias LISTENER
    Version TNSLSNR for Linux: Version 12.2.0.1.0 – Production
    Start Date 14-MAY-2020 10:12:47
    Uptime 0 days 0 hr. 8 min. 27 sec
    Trace Level off
    Security ON: Local OS Authentication
    SNMP OFF
    Listener Parameter File /ora01/app/oracle/product/12.2.0/db_1/network/admin/listener.ora
    Listener Log File /ora01/app/oracle/diag/tnslsnr/server/listener/alert/log.xml
    Listening Endpoints Summary…
    (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.1.102)(PORT=1539)))
    (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
    (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=server)(PORT=5500))(Security=(my_wallet_directory=/ora01/app/oracle/admin/orcl/xdb_wallet))(Presentation=HTTP)(Session=RAW))
    Services Summary…
    Service “ORA12CXDB” has 1 instance(s).
    Instance “ORA12C”, status READY, has 1 handler(s) for this service…
    Service “a50ca342f86bccc0e0536801a8c085de” has 1 instance(s).
    Instance “ORA12C”, status READY, has 1 handler(s) for this service…
    Service “orcl” has 1 instance(s).
    Instance “ORA12C”, status READY, has 1 handler(s) for this service…
    Service “orclpdb” has 1 instance(s).
    Instance “ORA12C”, status READY, has 1 handler(s) for this service…
    The command completed successfully

    and if I run the below command I get the same error:-

    ./sqlplus anju/anju@192.168.1.102/ORA12C

    SQL*Plus: Release 12.2.0.1.0 Production on Thu May 14 10:34:59 2020

    Copyright (c) 1982, 2016, Oracle. All rights reserved.

    ERROR:
    ORA-12541: TNS:no listener

    this is my listener.ora file:-

    LISTENER =
    (DESCRIPTION_LIST =
    (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.102)(PORT = 1539))
    (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
    )

    Could you please help..!!!

    1. Since your listener port is not the default one (1521), you should provide the port number in the connection string.

      sqlplus anju/anju@192.168.1.102:1539/ORA12C

  3. Thank you Ed ,but it gave me this error:-

    [oracle@server bin]$ ./sqlplus anju/anju@192.168.1.102:1539/ORA12C

    SQL*Plus: Release 12.2.0.1.0 Production on Thu May 14 11:47:18 2020

    Copyright (c) 1982, 2016, Oracle. All rights reserved.

    ERROR:
    ORA-12514: TNS:listener does not currently know of service requested in connect
    descriptor

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