Connection to an oracle db from another computer 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:

ELIF =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.10.15.58)(PORT = 1521))
(CONNECT_DATA =
  (SERVER = DEDICATED)
  (SERVICE_NAME = ELIF)
)
)


When I make a tnsping I got the following error:

Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 10.10.15.58)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SID = ELIF)))
TNS-12541: TNS:no listener


Edit:
lsnrctl status and netstat -an | grep 1521 result:

oracle@cms:~$ lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 25-JAN-2012 13:26:16

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

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 11.2.0.1.0 - 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...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1521)))
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      0 127.0.0.1:1521          0.0.0.0:*               LISTEN     
tcp        0      0 127.0.0.1:32656         127.0.0.1:1521          ESTABLISHED
tcp        0      0 127.0.0.1:1521          127.0.0.1:32656         ESTABLISHED
unix  2      [ ACC ]     STREAM     LISTENING     115265   /var/tmp/.oracle/sEXTPROC1521
Type:

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.