How to Resolve ORA-12541: TNS:no listener

Oracle Database
February 13, 2019March 6, 2024
by Ed Chen
10 Comments

ORA-12541 and TNS-12541

ORA-12541 is the same as TNS-12541, they all indicate that the listener is not running according to your specified destination.

Let’s see how we reproduce ORA-12541 and TNS-12541.

SQL*Plus throws ORA-12541


SQL> conn hr/hr@orcl

ERROR:

ORA-12541: TNS:no listener

TNSPING throws 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:

The listener is not started.

This is the most common problem of ORA-12541 we have met. Just start it up and make sure it's running.

The listener is listening to another port other than the default one, e.g. 1522.

Backup port like 1522 may be used by the listener for connection, you should ask for DBA to handle it.

The connection went for the wrong database server.

Please check every parameter in your connect descriptor and make sure they are correct. Then connect again.

Routing to the wrong destination.

It's rare, but it did happen in a very complex network environment. Part of connections are routed by some network device to an unknown server where has no listener service on port 1521.

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 19c Net Services Administrator's Guide: 15 Testing Connections.

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Tags:lsnrctl No such file or directory ORA-12541 Port 1521 Port 1522 sqlplus TNS-12541 tnsping

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

Jon Carpenter February 25, 2020 at 4:06 pm

Reply

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!!
1. Ed Chen February 27, 2020 at 3:37 am
  
  Reply
  
  Thanks! It’s my honor to contribute the community.
asef March 8, 2020 at 4:02 pm

Reply

tnx solved my problem
1. Ed Chen March 9, 2020 at 5:24 am
  
  Reply
  
  My pleasure.
Anjana May 14, 2020 at 5:06 am

Reply

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/[email protected]/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. Ed Chen May 14, 2020 at 6:06 am
  
  Reply
  
  Since your listener port is not the default one (1521), you should provide the port number in the connection string.
  
  sqlplus anju/[email protected]:1539/ORA12C
Anjana May 14, 2020 at 6:22 am

Reply

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

[oracle@server bin]$ ./sqlplus anju/[email protected]: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
1. Ed Chen May 19, 2020 at 12:33 am
  
  Reply
  
  Please check the service name (NOT instance name) that you used in the connection string. Normally, the service and the instance name are the same, but in your case, it’s not.
  
  You may check the following post for more information: How to Resolve ORA-12514: TNS:listener does not currently know of service requested in connect descriptor.
Wafula Jude July 12, 2023 at 9:05 am

Reply

LSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
64-bit Windows Error: 61: Unknown error
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
64-bit Windows Error: 2: No such file or directory
LSNRCTL> start LISTENER
Starting tnslsnr: please wait…

Unable to OpenSCManager: err=5
TNS-12560: TNS:protocol adapter error
TNS-00530: Protocol adapter error
1. Ed Chen July 12, 2023 at 10:31 am
  
  Reply
  
  Try to start the listener by “Administrator” on Windows.