Define Oracle Listener Trace Level

In Oracle 11g R2, you can configure listener trace levels using Oracle Net Manager or by manually editing the `listener.ora` file. Below are the steps for both methods:
Method 1: Using Oracle Net Manager (GUI)

1. Launch Oracle Net Manager
   • On Windows:
     • Go to Start Menu → Oracle - [HOME_NAME] → Configuration and Migration Tools → Oracle Net Manager.
   • On Unix/Linux:
     • Run netmgr from the terminal (if $ORACLE_HOME/bin is in your PATH).
2. Navigate to Listener Configuration
   • Expand Local → Listeners in the left panel.
   • Select the listener you want to configure (e.g., LISTENER).
3. Configure Tracing
   • Go to the General Parameters tab → Logging & Tracing subtab.
   • Enable Tracing:
     • Check Trace Level and select:
       • OFF (No tracing)
       • USER (User-level tracing)
       • ADMIN (Administrative tracing)
       • SUPPORT (Detailed troubleshooting, generates large files)
   • Set Trace Directory & Filename (Optional):
     • Trace Directory: Where trace logs will be stored (e.g., $ORACLE_HOME/network/trace).
     • Trace File: Name of the trace file (e.g., listener.trc).
4. Save Changes
   • Click File → Save Network Configuration.
   • The changes will be written to listener.ora.
5. Restart the Listener
   • Run in Command Prompt/Terminal:

     lsnrctl stop
     lsnrctl start
               

1. Locate listener.ora
   • Typically found in:
     • $ORACLE_HOME/network/admin/listener.ora (Linux/Unix)
     • %ORACLE_HOME%\network\admin\listener.ora (Windows)
2. Add/Modify Trace Parameters Open listener.ora and add the following under your listener definition:
   

   TRACE_LEVEL_<LISTENER_NAME> = {OFF | USER | ADMIN | SUPPORT}
   TRACE_FILE_<LISTENER_NAME> = listener.trc
   TRACE_DIRECTORY_<LISTENER_NAME> = $ORACLE_HOME/network/trace
         

   Example:

   LISTENER =
     (DESCRIPTION_LIST =
       (DESCRIPTION =
         (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
       )
     )
   TRACE_LEVEL_LISTENER = SUPPORT
   TRACE_FILE_LISTENER = listener.trc
   TRACE_DIRECTORY_LISTENER = /u01/app/oracle/network/trace
         

3. Restart the Listener

   lsnrctl stop
   lsnrctl start
         

Verifying Trace Settings

• Check current listener settings:

  lsnrctl status
        

• View trace files in the specified directory (e.g., listener.trc).

Important Notes

• SUPPORT level generates very large logs (use only for troubleshooting).
• Ensure the TRACE_DIRECTORY exists and has write permissions.
• Oracle 11g R2 still supports both GUI (netmgr) and manual (listener.ora) methods.

To define **trace levels for the listener** using **Oracle Net Manager** in **Oracle 23ai**, follow these updated steps:
🧭 Steps in Oracle Net Manager (for Listener Tracing)

1. Launch Oracle Net Manager
   • On Linux: Run netmgr from the terminal.
   • On Windows: Go to Start > Oracle - > Net Manager.
2. Navigate to the Listener Configuration
   • In the left pane, expand:

     Local > Listeners > LISTENER
             

   • (Replace LISTENER with the actual name if different.)
3. Enable Logging and Tracing
   • Click the "Logging and Tracing" tab (under the selected listener).
   • Select the "Tracing" sub-tab.
4. Set the Trace Level
   • From the Trace Level dropdown, choose one of the following:
     • OFF – No trace output.
     • USER – Captures errors relevant to end-users.
     • ADMIN – Captures all errors, including network and protocol issues.
     • SUPPORT – Reserved for Oracle Support (very verbose).
5. (Optional) Customize Additional Parameters
   • Trace File Name: Set a custom file name if desired.
   • Trace Directory: Specify the directory where the trace file should be saved (default is $ORACLE_HOME/network/trace).
6. Save the Configuration
   • Click File > Save Network Configuration.
7. Restart the Listener
   • To apply changes:

     lsnrctl stop
     lsnrctl start
             

   • Or use lsnrctl reload if no restart is needed.

📁 Resulting Configuration in `listener.ora`
After saving changes via Oracle Net Manager, your `listener.ora` will include entries like:

TRACE_LEVEL_LISTENER = ADMIN
TRACE_DIRECTORY_LISTENER = /opt/oracle/product/23ai/network/trace
TRACE_FILE_LISTENER = listener.trc

🛠 Tipss

• Avoid setting the trace level to SUPPORT in production unless directed by Oracle Support—it may generate large files quickly.
• If you don’t see Oracle Net Manager, ensure that the Oracle Database client or full database install includes it (it’s part of the GUI tools bundle).