I have installed Oracle 11g to an ubuntu, I can connect to DB using sqlplus from the localhost, But I cannot connect from another computer, I have configured my tnsnames.ora as followed;


when I make a tnsping I got the following error;

Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SID = ELIF))) TNS-12541: TNS:no listener

Edit: "lsnrctl statu" and "netstat -an | grep 1521" results.

oracle@cms:~$ lsnrctl status

LSNRCTL for Linux: Version - Production on 25-JAN-2012 13:26:16

Copyright (c) 1991, 2009, Oracle.  All rights reserved.

Alias                     LISTENER
Version                   TNSLSNR for Linux: Version - Production
Start Date                25-JAN-2012 02:33:02
Uptime                    0 days 10 hr. 53 min. 13 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File /home/oracle/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File         /home/oracle/app/oracle/diag/tnslsnr/cms/listener/alert/log.xml
Listening Endpoints Summary...
Services Summary...
Service "ELIF" has 1 instance(s).
  Instance "ELIF", status READY, has 1 handler(s) for this service...
Service "ELIFXDB" has 1 instance(s).
  Instance "ELIF", status READY, has 1 handler(s) for this service...
The command completed successfully

oracle@cms:~$ netstat -an | grep 1521
tcp        0      0*               LISTEN     
tcp        0      0          ESTABLISHED
tcp        0      0         ESTABLISHED
unix  2      [ ACC ]     STREAM     LISTENING     115265   /var/tmp/.oracle/sEXTPROC1521
  • We had the same problem, but with different cause.Though listener was configured to listen on server hostname, it really was listening on loopback interface only. The issue was in /etc/hosts file. It contains server hostname in line related to loopback (starting with Remowing server hostname from that line solved our problem. – user13330 Oct 10 '12 at 11:58


lsnrctl start

On your Unix box. That starts the listener.

If you still can't connect after that it's either a firewall issue or the listener isn't configured.

  • my listener is started, and I can connect in linux box. my listener configuration is as followed can you help me with that configuration. – dursun Jan 25 '12 at 7:41
  • Post the results of the following: "lsnrctl status" and "netstat -an | grep 1521". I suspect it's the listener only listening on localhost or your firewall's turned on. – Philᵀᴹ Jan 25 '12 at 8:05
  • I have edited my question for lsnrctl status and netstat. – dursun Jan 25 '12 at 8:35
  • 1
    Ok, it's only listening on localhost. You need to edit /home/oracle/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora and replace "localhost" or "" with the hostname of the linux box (it'll be after "HOST=" in the file). Then type "lsnrctl reload" – Philᵀᴹ Jan 25 '12 at 9:14

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