oracle-databaselistenertnsnames

"ORA-12541: TNS:no listener" but there are log entries in the listener log

I am using SQLPlus on a remote machine and after I put in my username and password it says "ORA-12541: TNS:no listener", but when I look at the listener log on the Oracle 19c server, there is an entry showing the connection. What am I doing wrong?

I was trying to log in to SQLPlus when I got the error.

Here are my test results:

  1. TNSPing Server Test Results: Attempting to contact (ADDRESS = (PROTOCOL = TCP)(HOST = 10.100.132.16)(PORT = 1521)) OK (30 msec)

  2. Yes, I can connect to sqlplus on the server

  3. lsnrctl status listener Services Summary... Service "CLRExtProc" has 1 instance(s). Instance "CLRExtProc", status UNKNOWN, has 2 handler(s) for this service... Service "RADB" has 1 instance(s). Instance "RADB", status UNKNOWN, has 1 handler(s) for this service... The command completed successfully

  4. TNSPing Client Test Results: Message 3513 not found; No message file for product=NETWORK, facility=TNSMessage 3509 not found; No message file for product=NETWORK, facility=TNS

  5. Telnet OK

Solution

  • It seems you are with wrong configuration environment variables, and my guess is you are trying to connect from a windows machine as client, correct?

    Does the ORACLE_HOME was set at the System / Environment level on the Windows client? Do you have more than one Oracle Client installed?

    You can try going to the Oracle Home Client bin folder, unset the ORACLE_HOME env (if is it set).

    Test in a CMD prompt session like:

    E:>\oracle\product\12.1\client_1\bin>set ORACLE_HOME=

    Now try to TNSPing again. The "no message file" errors should clear.

    Is it the TNS_ADMIN env set? If not, you can try to set it to the correct ORACLE_HOME\network\admin folder, with the correct tnsnames.ora configured to your database.

    Are you trying to connect with a user common account or using the sys as sysdba?