I am new on Oracle database, but I have one issue.
On my Database server (server1) listener and database instance run correctly and I can use sqlplus
to connect to this DB.
When I connect to database by using other server, I check the TNS configuration and it is correct but system says:
ERROR: ORA-12541: TNS:no listener
My database is Oracle 10gR2
So how can I solve this issue?
According to oracle online documentation
ORA-12541: TNS:no listener
Cause: The connection request could not be completed because the listener is not running.
Action: Ensure that the supplied destination address matches one of the addresses used by
the listener - compare the TNSNAMES.ORA entry with the appropriate LISTENER.ORA file (or
TNSNAV.ORA if the connection is to go by way of an Interchange). Start the listener on
the remote machine.
I also faced the same problem but I resolved the issue by starting the TNS listener in control panel -> administrative tools -> services ->oracle TNS listener start.I am using windows Xp and Toad to connect to Oracle.
Check out your TNS Names, this must not have spaces at the left side of the ALIAS
Best regards
You need to set oracle to listen on all ip addresses (by default, it listens only to localhost connections.)
listener.ora
This file is located in:
%ORACLE_HOME%\network\admin\listener.ora
.Replace localhost
with 0.0.0.0
# ...
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = 0.0.0.0)(PORT = 1521))
)
)
# ...
Windows: WinKey + r
services.msc
Linux (CentOs):
sudo systemctl restart oracle-xe
Source: Stackoverflow.com