Network Topology   «Prev  Next»

Lesson 2 The Net parameter files
Objective Describe the function of Net parameter files

Function of Oracle Net Parameter Files

Here's a description of Net parameter files in Oracle Network Services: Purpose:
  • Store configuration settings that govern how Oracle Net clients and servers communicate within a network.
  • These files streamline configuration management and ensure consistent network behavior across multiple applications.

Key types:
  1. sqlnet.ora:
    1. Primary Net parameter file.
    2. Contains global settings applicable to all Oracle Net connections on a client or server.
    3. Controls features like:
      • Logging and tracing
      • Security features
      • Advanced connection options
      • Network routing
  2. tnsnames.ora:
    • Repository for net service names (aliases for describing database connection information).
    • Maps user-friendly names to full connect descriptors, simplifying connection establishment.
  3. listener.ora:
    • Configures Oracle Net Listeners, processes that listen for incoming connection requests on a server.
    • Specifies details like:
      1. Listener name
      2. Network address and port
      3. Services to register with the listener
  4. cman.ora:
    • Used for clustering environments to manage Oracle Connection Manager (CMAN) configuration.

  • Typically reside in the `$ORACLE_HOME/network/admin` directory on both clients and servers.

  • Manual editing with a text editor.
  • Oracle Net Configuration Assistant (NETCA) tool for guided configuration.

  • Crucial for establishing and managing Oracle database connections across networks.
  • Proper configuration ensures successful communication and optimizes performance and security.

At this point, it is necessary to make an important distinction about Net management. As we mentioned, Oracle has provided several online interfaces to assist with Net configuration and management. These GUI tools include:
  1. Oracle Net Configuration Assistant
  2. Oracle Connection Manager: The Oracle Connection Manager Control utility enables you to administer Oracle Connection Managers. You can use its commands to perform basic management functions on one or more Oracle Connection Managers. Additionally, you can view and change parameter settings.
  3. A router through which a client connection request may be sent either to its next hop or directly to the database server. Clients who route their connection requests through an Oracle Connection Manager can then take advantage of the session multiplexing, access control, or protocol conversion features configured on that Oracle Connection Manager.
  4. Enterprise Manager

Large Oracle Installations

However, please note that these tools are not always suitable for large Oracle installations, especially those that are still running legacy Oracle versions. In addition, these tools are only front ends that populate the Oracle configuration files, and many experienced administrators prefer to edit the parameter files directly without the use of the GUI tools. Hence, an understanding of the syntax and functions of the parameter files is critical to a full understanding of Net.
In Oracle, any computer can serve as a Net client, a Net server, or as both a client and a server.


Purpose: To set a unique identifier for the client computer. This identifier is passed to the listener with any connection request and is included in the Audit Trail. The identifier can be any alphanumeric string up to 128 characters long.
Default: None Example

The following bullet points describe creating Net client using Legacy Oracle Net8 Technology

Creating a Net client

There are two steps to creating a Net client on a Windows computer:
  1. Run the Oracle installer to install the Net client-software component. This process places the Net software in the c:\orawin directory for Windows, or the c:\orant directory for Windows NT clients.
  2. Create a tnsnames.ora file to establish connectivity to the remote database. This can be done with Net Easy Config, but most corporations have a pre-built tnsnames.ora file that can be copied into the c:\orant\network\admin\location (or the c:\orant\net80\admin directory for Net).

Creating a Net Server

To create a Net server, you need only install an Oracle database and create and successfully configure a listener.ora file to start the listener process. Once the files are properly configured, connectivity can be established by entering SQL*Plus and entering the TNS service name of the desired database. That is all there is to Net. If this sounds simplistic, it is because we have not yet looked into the internals of the parameter files. We will do so shortly.
In the next lesson, we will look at the components of Oracle Network Services.