6
Configuring the Network

This chapter describes how to configure your network.

Specific topics discussed are:

• Configuration Overview
• Using the Host Naming Method
• Using the Local Naming Method
• Using the Oracle Names Method
• Configuring Oracle Connection Manager
• Testing the Configuration on the Server
• Testing the Configuration on the Client

Configuration Overview

Before a database server can receive connections from clients, clients must be configured with service names (easy to remember aliases for database addresses) that match the address preconfigured in each server machine's LISTENER.ORA file. These addresses are used by the client to connect to the network listener during a connection. During a connection, a client passes the system ID (SID) of the server to which it wants to connect.

The LISTENER.ORA file identifies and controls the behavior of the network listeners that listen for the databases on the machine. This file includes network listener descriptors and addresses of all network listeners on a machine, the SIDs of the databases they listen for, and various control parameters.

Client configuration is accomplished by creating a list of the service names and addresses of network database destinations through a TNSNAMES.ORA client configuration file or an Oracle Names Server. A client (or a server that is part of a distributed database) needs this information to know where to make connections.

Configuration is based upon one of two models:

Network Configuration Model	Suitable When...	Naming Method	Configuration Tool
Localized management	Network addresses are mapped in a TNSNAMES.ORA file on each node (no Oracle Names Server).	Host naming   Local naming   External naming	Net8 Easy Configuration Tool
Centralized management	Networks where an Oracle Names Server performs network address resolution. An Oracle Names Server stores client configuration profiles in one location.	Oracle Names	Oracle Net8 Assistant

 

Naming Methods

Service names can be created using the following configuration methods:

Naming Method	Description
Host Naming	Resolves service names through a TCP/IP network's Domain Name System (DNS) or in the /ETC/HOSTS file. This method is recommended for simple TCP/IP environments.   See "Using the Host Naming Method" in this chapter.
Local Naming (no Oracle Names Server)	Resolves service names to network addresses by using information configured and stored on each individual client. Local Naming is most appropriate for simple distributed networks with a small number of services that change infrequently.   See "Using the Local Naming Method" in this chapter.
Oracle Names	Stores names and addresses of all database services on a network on an Oracle Names Server. Connection requests are routed through an Oracle Names Server, which resolves the service name to a network address. The information is then returned to the client.   See "Using the Oracle Names Method" in this chapter.
External Naming	External naming refers to service name resolution by using a supported third-party naming service.   See "Using the External Naming Method" in Chapter 8, "Performing Advanced Configuration".

 

Configuration Files

Depending on the naming method you use, the following configuration files may be created or updated in ORACLE_HOME\NET80\ADMIN:

Configuration File	Description
LISTENER.ORA	Includes addresses of all network listeners on a server, the SIDs of the databases for which they listen, and various control parameters used by the network listener. This file resides on the server.
TNSNAMES.ORA	Includes a list of service names of databases. This file resides on clients.
SQLNET.ORA	Includes the names resolution method. This file resides on clients.
SDNS.ORA	Includes lists of Oracle Names Servers. This file resides on clients.

 

Additional Information:   See Appendix C, "Configuration Files" for more information about these files.

   

Using the Host Naming Method

The host naming method is enabled by default during Typical installation for TCP/IP network environments only. The LISTENER.ORA has a line which specifies the TCP/IP host name of your server. Clients that use this host name in their connect string can connect.

Your client machine may connect to a database using the host name of the machine on which the database resides if:

• you are connecting to an Oracle8 database with Net8 Server/Client software installed
• your client and server are connecting over a TCP/IP protocol
• all names are resolved through an IP address translation mechanism such as DNS, or a centrally maintained TCP/IP hosts file
• no advanced features like Oracle Connection Manager are requested or required

Server Configuration

Ensure GLOBAL_DBNAME = HOSTNAME as specified in the ORACLE_HOME\NET80\ADMIN\LISTENER.ORA configuration file, where HOSTNAME is the TCP/IP host name or alias of the server system.

During the installation of Net8, the GLOBAL_DBNAME of the default database is set to the system name.

To verify GLOBAL_DBNAME is correctly specified, manually check the LISTENER.ORA file of use the Oracle Net8 Assistant:

Check the LISTENER.ORA file...

Use the Oracle Net8 Assistant...

Ensure the line shown in bold exists:  SID_LIST_LISTENER_NAME=    (SID_LIST =       (SID_DESC =          (SID_NAME = SID)          (GLOBAL_DBNAME = HOSTNAME)       )    )

Choose Start > Programs > Oracle for Windows NT - HOME_NAME > Oracle Net8 Assistant.  The Oracle Net8 Assistant starts.  Double-click the Listeners folder.  Select the appropriate network listener from the Listeners folder.  The network listener details appear on the right side of the screen:  Select Database Services from the drop-down list.  Ensure the TCP/IP host name is correctly specified in the Global Database Field.  Choose Save Network Configuration from the File menu.  Choose Exit from the File menu to exit the Oracle Net8 Assistant application.

 

Client Configuration

No client configuration is necessary for using the Host Naming Adapter. The connection is established by using the default TCP/IP port for the network listener.

Multiple Databases On a Server

If you have multiple databases on a server, you can set TCP/IP aliases for the server system, and assign a separate GLOBAL_DBNAME parameter for each different databases in the LISTENER.ORA file.

The client will then connect to the specific database based on the host name used for connection.

Using the Local Naming Method

With the local naming method, service names are added to the TNSNAMES.ORA files. Service names are mapped to database address. Clients use this service name in their connect string to connect.

Server Configuration

To configure using the local naming method:

Note:   Net8 Easy Configuration Tool only supports configurations using TCP/IP, SPX, Named Pipes, and Bequeath Protocol Adapters. To configure a service name using the LU6.2 Protocol Adapter, you must manually edit the configuration files.

   

1. Choose Start > Programs > Oracle for Windows NT - HOME_NAME > Net8 Easy Configuration Tool.

The Oracle Net8 Easy Config wizard starts:


2. Enter a new service name (up to 64 characters) in the New Service Name field to create a new service name, and click Next. The service name can be any name you choose.

The next page appears:


3. Select the network protocol you want to use (this protocol adapter must also be installed on the clients), and click Next.

The page appropriate for your protocol adapter appears; in the example here, TCP/IP is assumed:


4. Enter the appropriate information for your chosen protocol in the fields, and click Next.

The next page appears:


5. Enter the name of the SID of the database to which you want to connect in the Database SID field, and click Next. The default SID is ORCL.

The following page appears:


6. Click Next (testing is performed later in this chapter).
7. Click Finish to save your configuration and quit the Net8 Easy Configuration Tool.

Oracle Net8 Easy Config adds the new service names to the TNSNAMES.ORA in ORACLE_HOME\NET80\ADMIN.

8. If you have more than one supported Oracle Protocol Adapter in your ORACLE_HOME directory, use Net8 Easy Configuration Tool to configure other services following the same steps.

Client Configuration

After the server is configured, it is best to simply copy over the TNSNAMES.ORA configuration file located at ORACLE_HOME\NET80\ADMIN on the server to the same location on the clients. This will ensure the files are consistent. Otherwise, you must use the Oracle Net8 Easy Config tool on every client, introducing possible errors.

Using the Oracle Names Method

Oracle Names simplifies the setup and administration of global, client/server computing networks. Oracle Names makes network address and database link information available to all nodes throughout the network. Each database server's network address is identified with a simple service name. Client applications then can request a database connection with that name rather than a lengthy address.

Oracle Names is made up of Names Servers that store a service's name and network address. Services include databases, database link definitions, and object aliases. Client applications request a connection using a simple name, rather than the lengthy address, and the name is resolved to the address by a Names Server. Oracle Names shields users and applications from changes made to the network infrastructure. It provides for centralized administration of network service names.

The diagram below shows that:

• (1) Oracle services can dynamically register themselves with Oracle Names Servers.
• (2) Clients seeking to locate a service on an Oracle network contact their closest Oracle Names Server to retrieve the network address.
• (3) Clients then transparently connect to the service.

 

Oracle Names Features

The automatic discovery feature of Oracle Names version 8 enables network connectivity with virtually no configuration files.

Oracle Names version 8 includes three features to improve network performance and ease of administration:

• Dynamic Service Registration
• Client Discovery of Names Servers
• Client Caching of Oracle Names Servers




Feature	Description
Dynamic Service Registration	With dynamic service registration, a Net8 network listener automatically locates a Names Server through the mechanism of a well-known address and registers its services with Oracle Names. A single database network listener can service connection requests for several database instances. At startup, the network listener forwards connect descriptors and global names for each of these services. When the service or network listener is shut down, the network listener automatically deregisters its services with Oracle Names.   The network listener registers with the Oracle Names Servers by looking for a Names Server with a well-known address. The well-known Names Server address on a TCP/IP network is a host aliased to oranamesrvr0, oranamesrvr1,...oranamesrvr4, using port 1575.   Once the service is registered, its address is made available to all other Names Servers in the region. The address information is shared in one of two ways:  Service Replication -- In service replication, service information is stored in a Names Server's cache and is instantly replicated to the caches of all other Names Servers.  Oracle Names database -- If an Oracle database is used as the registration repository, the registration information is stored in the database, and from there is accessible to all the Names Servers.
Client Discovery of Names Servers	The discovery process involves running an REORDER_NS command from the NAMESCTL80 utility or choosing Discover Oracle Names Server (from  the Tools menu) in the Net8 Assistant. This produces a SDNS.ORA file in the ORACLE_HOME\NET80\NAMES directory. This file contains a list of the Oracle Names Servers the client can connect.   The discovery process allows the client to:  retrieve a list of all of the existing Names Server addresses with minimal network configuration at installation  find out about new Names Servers as they appear in the network.  This allows for dynamic changes in the network topology with minimal involvement on the user's part and with little or no impact on the performance of a normal query.   Clients discover Names Servers in much the same way that services find them for registration:  A client first looks in its own SDNS.ORA client cache file. If it has contacted a Names Server within the past 24 hours, the address of a Names Server may be in the cache.  A client looks for a Names Server with a well-known address. The well-known Names Server address on a TCP/IP network is a host aliased to oranamesrvr0, oranamesrvr1,...oranamesrvr4, using port 1575.  Once a Names Server is found, the addresses of all the other version 8 Names Servers in the region are made available to the client.
Client Caching of Oracle Names Servers	After the clients have discovered Oracle Names Servers, the SDNS.ORA client cache file can simply be updated with new Oracle Names Server information by starting the OracleHOME_NAMEClientCach80 service on the client(s).   OracleHOME_NAMEClientCache80 contacts each of the Names Servers in turn, and orders the list on the basis of the speed of each Names Server's response. Subsequently, when a client makes a query to a Names Server, the Names Server at the top of the list in the SDNS.ORA file is contacted first.   The local client-side cache is particularly advantageous if at some time no Names Server is available. In this case, the local client-side cache has the current list of recently accessed services.   All the information in the client cache has a time to live (TTL). At the end of that TTL, the information is flushed from the cache. The purpose of this feature is to avoid having stale information in the client cache. The default TTL is 86,400 seconds (24 hours). It cannot be changed.

   

Differences Between Versions of Oracle Names

There are significant differences between this version of Oracle Names and earlier versions:

• In Oracle Names version 1, administrators configured Names Servers using Oracle Network Manager and stored all topology data in a database. All the Names Servers in a region shared the same information because they accessed the same database.
• In Oracle Names version 2, the administrator could choose between continuing Names Server configuration as in version 1, or using the Dynamic Discovery Option. The Dynamic Discovery Option was recommended only for a network with a flat namespace (that is, only one domain). If the Dynamic Discovery Option was chosen, no database was needed; each Names Server automatically replicated its data to all other well-known Names Servers in the region. Network listeners could register themselves with well-known Names Servers and clients could find them without configuration. Otherwise, Oracle Names could be used just as the earlier version had been.
• Oracle Names version 8 takes the features of the Dynamic Discovery Option and expands on them significantly. Included among the differences are the following:
• A service can register itself with any Names Server it can find, and its name and address are made available to all Names Servers in the region. Similarly, if an administrator manually registers a service to any Names Server, that service information is available to all other Names Servers.
• A client-side process times the connections from the client to all Names Servers in the region, and maintains an ordered list so that the client queries the Names Server that has the shortest response time first. Clients using SQL*Net version 2.3. are able to take advantage of this feature.
• On most platforms, the client maintains a client-side cache that includes the results of the client's queries to the Names Servers. This feature improves performance as it reduces the number of client-Names Server queries.
• Oracle Names version 8 does not require a database to hold topology information. However, an administrator may choose to use one, and it is recommended.

Setting Up and Oracle Names Server

The steps to set up an Oracle Names Server include:

Step 1: Install

Step 2: Configure the Server

Step 3: Define a Well-Known Oracle Names Server

Step 4: Create a Well-Known Oracle Names Server

Step 5: Configure Clients and Servers To Use Oracle Names Server

Step 1: Install

Ensure the following are installed:

• Oracle Names Server on its own machine that is designated as the Oracle8 Server
• Net8 Client on the clients
• Net8 Server on the server
• TCP/IP, or Named Pipes or SPX on all clients

Note:   Oracle Names Server only supports TCP/IP, Named Pipes and SPX Protocol Adapters.

   

Additional Information:   See "Verifying Installation and Setup" in Chapter 3, "Understanding Post Installation Tasks" to verify installation and the CD-ROM insert for more information about the Oracle Installer and its options.

   

Step 2: Configure the Server

On the server, the network listener must be configured to identify a database listener on that server for an Oracle Names Server.

To configure the network listener:

1. From the Control Panel window, double-click Services.

The Services window appears.

2. Check the status of the network listener OracleHOME_NAMETNSListener. If the network listener is stopped (the status column is blank), go to the Step 3. If the status is Started, stop the network listener:

To stop the network listener:

1. From the Control Panel's Services window, select OracleHOME_NAMETNSListener80 (the service name if you are using the default network listener name LISTENER) or OracleHOME_NAMETNSListener80LSNR (where LSNR is the non-default network listener name), and click Stop.

The Services confirmation dialog box appears, prompting you if it is OK to stop the service.

2. Click Yes.

The network listener is stopped. The status column is blank.

3. Click Close to quit the Services window.
4. Set the global database name and register services with the Oracle Names Server using the Oracle Net8 Assistant or editing the ORACLE_HOME\NET80\ADMIN\LISTENER.ORA file.

The global database name specifies the name by which the network listener registers the database instance with an Oracle Names Server and the name by which the Oracle Names Server identifies a database. You can use any alias, but Oracle Corporation recommends setting the global database name to the value of the INITSID.ORA's DB_NAME and DB_DOMAIN parameters. The default global database name is ORACLE.WORLD.


When clients request the connect information for a database from an Oracle Names Server, this is the alias they use. The domain must also be added to the end of this name.


Registering services with the Oracle Names Server instructs the network listener to find and register with a well-known Oracle Names Server. When the network listener starts, it looks for hosts with the well-known host names, tries to gather connection information from the Oracle Names Server, and registers its SID(s) with it.



Use the Net8 Assistant...

Modify the LISTENER.ORA file...

Choose Start > Programs > Oracle for Windows NT - HOME_NAME > Oracle Net8 Assistant.  The Oracle Net8 Assistant starts.  Double-click the Listeners folder.  Select the appropriate network listener from the Listeners folder.  The network listener details appear on the right side of the page:  Select Database Services from the drop-down list.  Modify the Global Database Field with the an alias. Preferably, use the values of DB_NAME and DB_DOMAIN from the INITSID.ORA as the alias.  Select General Parameters from the drop-down list.  Select Register Services with Oracle Names.  Choose Save Network Configuration from the File menu.  Choose Exit from the File menu to exit the Oracle Net8 Assistant.

Ensure GLOBAL_DBNAME is set to an alias. Preferably, use the values of DB_NAME and DB_DOMAIN from the INITSID.ORA as the alias. For example:  SID_LIST_LISTENER_NAME=    (SID_LIST =       (SID_DESC =          (SID_NAME = SID)          (GLOBAL_DBNAME = GLOBAL_DBNAME.DOMAIN)       )    ) USE_PLUG_AND_PLAY_listener = ON

   

Step 3: Define a Well-Known Oracle Names Server

To define a well-known Oracle Names Server:

For all clients and servers, ensure your network administrator has named the Oracle Names Servers as a well-known names server, allowing clients to access the Oracle Names Servers using the well-known name.

Well-known names are dependent on the protocol adapter:

The well-known host names for TCP connections	The well-known computer Names for Named Pipes connections1	The well-known service name for an SPX connection
oranamesrvr0  oranamesrvr1  oranamesrvr2  oranamesrvr3  oranamesrvr4	ORANAMESRVR0  ORANAMESRVR1  ORANAMESRVR2  ORANAMESRVR3  ORANAMESRVR4	oranamesrvr

 

1 Well-known Names Server names for Names Pipes must be in all uppercase letters.

This implies you can have as few as one well-known Oracle Names Server (whose alias would be oranamesrvr0) and as many as five (with aliases oranamesrvr0 to oranamesrvr4).

The numbers 0 to 4 indicate the order in which the client tries to contact the Oracle Names Servers, if more than one exists in the network.

For example, for TCP/IP, Oracle Names Servers are made well-known by adding aliases oranamesrvr(0-4) to the Domain Name Service (DNS) or in the SYSTEMROOT\SYSTEM32\DRIVERS\ETC\HOSTS file.

The HOSTS file may include the following entries:

144.25.219.146 host0  oranamesrvr0
144.25.219.147 host1  oranamesrvr1
144.25.219.148 host1  oranamesrvr2

Step 4: Create a Well-Known Oracle Names Server

You may use the Oracle Names Control Utility (NAMESCTL80), or the Oracle Net8 Assistant to create a well-known Oracle Names Server on the machine where Oracle Names Server is installed.

Prior to creating a well-known Oracle Names Server, you must decide whether:

• You need support for one or more administrative regions. An administrative region consists of a collection of Oracle Names Servers in one or more domains.
• You need service registration data replicated continuously among Oracle Names Servers, or want Oracle Names Server to store their registration data in an Oracle database.

See Chapter 6, "Oracle Names," of the Oracle Net8 Administrator's Guide to help with these decisions.

Oracle Corporation recommends you create at two least Oracle Names Servers, one to act as the Oracle Names Server and one to act as a backup Oracle Names Server. Each of these should reside on its own machine.

To create a well-known Oracle Names Server, use the Oracle Net8 Assistant or the NAMESCTL control utility:

Use the Net8 Assistant...

Use the control utility NAMESCTL80...

If you want to create a region database, follow Steps 1-2 in Section 6.7, "Creating a Database to Store Names Server Information", of the Oracle Net8 Administrator's Guide.  On the machine where Oracle Names software resides, choose Start > Programs > Oracle for Windows NT - HOME_NAME > Oracle Net8 Assistant.  The Oracle Net8 Assistant starts.  Select the Oracle Names Servers folder.  A message appears, saying the Oracle Net8 Assistant does know of any Oracle Names Servers in the network.  Click OK to acknowledge message.  Choose Create from the Edit menu, or click on the "+" button to create a new Names Server.  The Names Wizard starts.  The wizard guides you through the creation and configuration process.  - a unique Oracle Name Server name  - an address for the Oracle Names Server  - a choice to store information in a database or replicate information among Oracle Names Server  If you choose to store information in a database, you are prompted for the listener address, and database SID, user name and password.  - to identify if this Oracle Names Server is in the root region  Choose Exit from the File menu to exit the Oracle Net8 Assistant application.  Repeat Steps 2-7 to create additional Oracle Names Servers on different machines within a region or another region. The Oracle Net8 Assistant does not support creation of multiple Oracle Names Servers on one machine.

If you want to create a region database, follow Steps 1-2 in Section 6,7, "Creating a Database to Store Names Server Information", of the Oracle Net8 Administrator's Guide.  Start the Oracle Names Server on each machine where Oracle Names software resides:  From the MS-DOS command prompt, enter:C:\> NAMESCTL80NAMESCTL> STARTOr, from the Control Panel's Services window, select OracleHOME_NAMENamesService80, and click Start.  Create a SDNS.ORA file in ORACLE_HOME\NET80\NAMES.  This file contains the names of the Oracle Names Server(s) in a particular region. The machine reads this file to find the addresses of other Oracle Names Servers.From the command line, enter:NAMESCTL> REORDER_NS

 

Step 5: Configure Clients and Servers To Use Oracle Names Server

To configure the client and server machines to recognize Oracle Names Servers, use the Oracle Net8 Assistant or the NAMESCTL control utility:

Use the Net8 Assistant...

Use the control utility NAMESCTL80...

Choose Start > Programs > Oracle for Windows NT/Windows 95/98 - HOME_NAME > Oracle Net8 Assistant.  The Oracle Net8 Assistant starts.  Select the Oracle Names Servers folder.  A message appears, saying the Oracle Net8 Assistant does know of any Oracle Names Servers in the network.  Choose Discover Oracle Names Servers from the Tools menu.  This produces an SDNS.ORA file in ORACLE_HOME\NET80\NAMES. This file contains the names of the Oracle Names Server(s). This file is read to find the addresses of Oracle Names Servers.The following message appears:"Discovered Oracle Names Server in the region. Please exit the tool and start again."  Choose Exit from the File menu to exit the Oracle Net8 Assistant application.

From the MS-DOS command prompt, enter:   C:\> NAMESCTL80   NAMESCTL> REORDER_NS   This produces an SDNS.ORA file in ORACLE_HOME\NET80\NAMES. This file contains the names of the Oracle Names Server(s). This file is read to find the addresses of Oracle Names Servers.

 

Ensure Oracle Names is the first method Net8 will use to reconcile service names by using the Oracle Net8 Assistant or editing the ORACLE_HOME\NET80\ADMIN\SQLNET.ORA file:

Use the Net8 Assistant...

Modify the SQLNET.ORA file...

Choose Start > Programs > Oracle for Windows NT/Windows 95/98 - HOME_NAME > Oracle Net8 Assistant.  The Oracle Net8 Assistant starts.  Click the Profiles icon.  The profile details appear on the right side of the page:  Select Naming from the drop-down list.  Click the Methods tab.  Choose ONAMES from the Available Methods list, and click <.  Select the ONAMES in the Selected Methods list, and click the Promote button to move the selection to the top of the list.  Choose Save Network Configuration from the File menu.  Choose Exit from the File menu to exit the Oracle Net8 Assistant application.  Oracle Names Server configuration is complete.

Add the NAMES.DIRECTORY_PATH parameter, so it includes ONAMES:NAMES.DIRECTORY_PATH = (ONAMES, TNSNAMES)   The order is important. Net8 tries to use the first method. If the first method fails to resolve the service name, Net8 tries to use the next method.   Oracle Names configuration is complete.

 

Configuring Oracle Connection Manager

The Oracle Connection Manager provides three capabilities for Oracle8:

• Connection Concentration

Allows you to multiplex multiple logical client sessions through a single transport connection to an Oracle server destination. This permits large numbers of users to access a single database which is running in multi-threaded server (MTS) mode, and thus increases the server's scalability. This feature is available only in a TCP/IP network.


Concentration reduces the demand on resources needed to maintain multiple connections between two processes by enabling the server to use fewer connection end points for incoming requests. This enables you to increase the total number of sessions that a server can handle. By using multiple Connection Managers, it is possible for thousands of concurrent users to connect to a server.

• Network Access Control

Provides a proxy for denying or allowing access to a database server. This feature, implemented only over the TCP/IP protocol, provides network filtering similar to that offered with a firewall.

• Multi-Protocol Support

Replaces the Multi-Protocol Interchange. Allows client and database servers operating on different protocol stacks to communicate with each other.

The clients require a TNSNAMES.ORA file or Oracle Names Server, the Oracle Connection Manager requires a CMAN.ORA, and the server requires multiplexing parameters set in the INITSID.ORA.

Conditions for Using Oracle Connection Manager

• TCP/IP must be installed and configured for local connectivity, because the Oracle Connection Manager Administration service (OracleHOME_NAMECMAdminService80) uses TCP/IP for communication with Oracle Connection Manager.
• The parameter AUTOMATIC_IPC=OFF must be set up in the SQLNET.ORA configuration file in order for a client to use Oracle Connection Manager.

Setting Up an Oracle Connection Manager

The steps to set up an Oracle Connection Manager include:

Step 1: Install

Step 2: Configure Clients

Step 3: Configure Oracle Connection Manager

Step 4: Configure the Server

Step 1: Install

Ensure the following are installed:

• Oracle Connection Manager on its own machine
• Net8 Client on the clients
• Net8 Server on the server

Additional Information:   See "Verifying Installation and Setup" in Chapter 3, "Understanding Post Installation Tasks" to verify installation and the CD-ROM insert for more information about the Oracle Installer and its options.

   

Step 2: Configure Clients

To configure the client:

Set the Oracle Connection Manager address through a TNSNAMES.ORA file or Oracle Names Server.

If using Oracle Names Server, the Oracle Connection Manager automatically updates the addresses in the Names Server, inserting the address for the CMAN into the existing address.

If you are using the local naming method, modify the ORACLE_HOME\NET80\ADMIN\TNSNAMES.ORA file located in ORACLE_HOME\NET80\ADMIN.

To modify the TNSNAMES.ORA file:

1. Choose Start > Programs > Oracle for Windows NT/Windows 95 - HOME_NAME > Oracle Net8 Assistant.

The Oracle Net8 Assistant appears.

2. Select the Service Names folder.

The list of current service names appears:


3. Select CMEXAMPLE.WORLD:
4. Modify the Address 1 tab with the address information for the Oracle Connection Manager.
5. Click Advanced.

The Advanced Options dialog box appears:


6. Ensure Source Route is checked, and click OK.

This option creates a source route of addresses through all Oracle Connection Managers to the destination address.

7. Select the Address 2 tab and modify it with the address information for the server. The second address is used by the Oracle Connection Manager to connect to the server.
8. You can have multiple CMAN addresses in the ADDRESS_LIST if necessary. The Oracle Connection Managers basically act as routers, pointing the connection request to the next hop.
9. Choose Save Network Configuration from the File menu.
10. Choose Exit from the File menu to exit the Oracle Net8 Assistant.

Below is a comparison of a regular TNSNAMES.ORA file and a TNSNAMES.ORA file with an entry to use the Oracle Connection Manager (Connection Manager entries are shown in boldface text):

INVENTORYDB.WORLD=     (DESCRIPTION=          (ADDRESS=                (PROTOCOL=TCP)                (HOST=INVENTORY)                (PORT=1521)          )         (CONNECT_DATA=                (SID=ORCL)         )      )

INVENTORYDB.WORLD=     (DESCRIPTION=         (ADDRESS_LIST=             (ADDRESS= <---CMAN address                (PROTOCOL=TCP)                 (HOST=CMAN)                 (PORT=1610) <---must match  port in CMAN.ORA file            )            (ADDRESS=                 (PROTOCOL=TCP)                 (HOST=INVENTORY)                 (PORT=1521)            )          )         (CONNECT_DATA=                (SID=ORCL)         )        (SOURCE_ROUTE=YES)      )

 

Enabling Multi-Protocol Support

Below is a TNSNAMES.ORA entry set up to use the Oracle Connection Manager with multiple protocols:

INVENTORYDB.WORLD= 
   (DESCRIPTION= 
       (ADDRESS_LIST= 
           (ADDRESS= 
               (PROTOCOL=SPX) 
               (SERVICE=CMAN) 
          (ADDRESS= 
               (PROTOCOL=TCP) 
               (HOST=INVENTORY) 
               (PORT=1521) 
          ) 
        ) 
       (CONNECT_DATA= 
              (SID=ORCL) 
       ) 
      (SOURCE_ROUTE=YES) 
    )

In this example, the client will use SPX to connect to the CMAN, then the CMAN will use TCP/IP to connect to the server. This is the same functionality that was provided with the Oracle Multi-Protocol Interchange (MPI) of Oracle7.

Step 3: Configure Oracle Connection Manager

Configuration of the Oracle Connection Manager may require the modification of the CMAN.ORA file located in ORACLE_HOME\NET80\ADMIN if you are using protocol adapters other than TCP/IP or require additional features.

Non-TCP/IP Protocol Adapters

If you used protocols other than TCP/IP between the client and 
Oracle Connection Manager, you must modify the line beginning  CMAN = 
(ADDRESS_LIST=

to listen to the protocols adapter address the same way you would modify LISTENER.ORA file.

Enabling Connection Concentration

Section 7.3.2, "Enabling Connection Concentration Features," of the Oracle Net8 Administrator's Guide explains how to enable multiplexing.

Enabling Specifying Network Access Control Rules

Section 7.3.3, "Enabling Connection Concentration Features," of the Oracle Net8 Administrator's Guide explains how to enable network access rules.

Enabling Optional Parameters

If you require other optional parameters, you must remove the `#' preceding those parameters from the CMAN.ORA file.

Additional Information:   See "Understanding the CMAN.ORA File" in Appendix C, "Configuration Files" for a complete description of the CMAN.ORA file and its parameters.

   

Step 4: Configure the Server

To use the multiplexing, configure the server for Multi-Threaded Server (MTS) by setting MTS parameters in the ORACLE_HOME\DATABASE\INITSID.ORA for each instance. See Appendix B, "Initialization Parameter Files", in your Getting Started guide.

Testing the Configuration on the Server

Once you have configured the network, test the configuration by performing a loopback test on the server.

 A loopback test uses Net8 to go from the server back to itself, bypassing the Interprocess Communication (IPC). Performing a successful loopback verifies that Net8 is functioning on the server side.

The steps to test the configuration are:

Step 1: Start Oracle Names Server

Step 2: Start the Network Listener

Step 3: Start Oracle Connection Manager

Step 4: Perform a Loopback Test

Step 1: Start Oracle Names Server

If you are using Oracle Names, start an Oracle Names Server on the machine where Oracle Names Server is installed and configured with the NAMESCTL80 control utility or the Control Panel:

Use the control utility NAMESCTL80...

Use the Windows NT Control Panel...

From the command line, enter:  C:\> NAMESCTL80NAMESCTL> STATUSIf the STATUS command indicates the Oracle Names Server is running, go to Step 3. If the Oracle Names Server is not running, go to Step 2.  Start the Oracle Names Server. Enter:  NAMESCTL> START  Exit from the NAMESCTL utility. Enter:  NAMESCTL> EXIT

From the Control Panel window, double-click Services.  The Services window appears. Look for the OracleHOME_NAMENamesService80 service. A blank in the Status column indicates that the service is not running. If the service is already running, close the window and go to the section "Step 2: Start the Network Listener".  Select the service, and click Start.  The service starts.  In the Services window, click Close.

 

Step 2: Start the Network Listener

For Net8 to accept connections on the server, a network listener must be started. If you have started an Oracle Names Server, the network listener upon startup automatically registers the databases specified in the SID_LIST_LISTENER_NAME section of the ORACLE_HOME\NET80\ADMIN\LISTENER.ORA file with the well-know Oracle Names Servers.

On the server, start the listener with the LSNRCTL80 control utility or the Control Panel:

Use the control utility LSNRCTL80...

Use the Windows NT Control Panel...

From the command line enter:  C:\> LSNRCTL80LSNRCTL> STATUS LISTENER_NAME where LISTENER_NAME is the name of the network listener defined in the LISTENER.ORA file with the alias LISTENER. It is not necessary to identify the network listener if you are using the default network listener, named LISTENER.If the STATUS command indicates the network listener is running, go to Step 2. If the network listener is not running, go to Step 3.  Even if the network listener is running, Oracle Corporation advises you to stop the network listener, and start it again. To stop the network listener, enter:  LSNRCTL> SET PASSWORD PASSWORD LSNRCTL> START LISTENER_NAME  SET PASSWORD is only required if the password is set in the LISTENER.ORA file. The password defaults to ORACLE.  Start the network listener. Enter:  LSNRCTL> START LISTENER_NAMEOracleHOME_NAMETNSListener80LSNR is created if this command is run for the first time against a non-default network listener name.  Exit from the LSNRCTL80 utility. Enter:  LSNRCTL> EXIT

From the Control Panel window, double-click Services.  The Services window appears. Look for OracleHOME_NAMETNSListener80 (the service name if you are using the default network listener name LISTENER) or OracleHOME_NAMETNSListener80LSNR (where LSNR is the non-default network listener name). OracleHOME_NAMETNSListener80LSNR is only created if the following command has been run:LSNRCTL80 START LISTENER_NAMEA blank in the Status column indicates that the service is not running. If the service is already running, close the window and go to the section "Step 3: Start Oracle Connection Manager".  Select the service, and click Start.  The service starts.  In the Services window, click Close.

 

Step 3: Start Oracle Connection Manager

If you are using Oracle Connection Manager, start it on the machine where Oracle Connection Manager is installed and configured with the CMCTL80 control utility or the Control Panel:

Use the control utility CMCTL80...

Use the Windows NT Control Panel...

From the command line, enter:  C:\> CMCTL80CMCTL> START CMAN  Exit from the CMCTL80 utility. Enter:  CMCTL> EXIT

From the Control Panel window, double-click Services.  The Services window appears.  If you are using Oracle Names, select the OracleHOME_NAMECMAdminService80 and click Start. If you are not using Oracle Names, do not start this service, and go to Step 3.  The service starts.  Select the OracleHOME_NAMECManService80, and click Start. A blank in the Status column indicates that the service is not running.  The service starts.  In the Services window, click Close.

 

Step 4: Perform a Loopback Test

A loopback test is when the server makes a connection to a database on its own machine.

Note:   The instructions below only apply if you have configured using the local naming method. If you have not configured with the local naming method, connect to the database using the instructions in "Step 5: Connect to the Database" of Chapter 7, "Connecting To a Database".

   

To perform the loopback test:

1. Choose Start > Programs > Oracle for Windows NT - HOME_NAME > Net8 Easy Configuration Tool.

Oracle Net8 Easy Config starts.

2. Click Test.
3. Select a service name from the Existing Services list box you created in "Using the Local Naming Method" in this chapter.
4. Click Next.

The Connection Test page appears:


5. Enter a valid user account user ID and password, such as SYSTEM and MANAGER, for the database you want to connect to, and click Test. The database administrator can provide this information.

The status of the test appears in the field below the Test button. A successful test display the following message:

The connection test was successful.

6. Click Done when the test is complete.

The final page appears.

7. Click Finish to dismiss Net8 Easy Configuration Tool wizard.

Testing the Configuration on the Client

After performing a loopback test, use any of the mechanisms below to test client connections:

• Verify TCP/IP Network Connections (if you are using TCP/IP)
• Verify Oracle Database Connections Using TNSPING
• Verify Oracle Database Connection Using Net8 Easy Configuration Tool

Verify TCP/IP Network Connections

If you are using TCP/IP, follow the instructions below to specify the destination address for TCP/IP and use PING to see if the server is running.

Determine the Server's IP Address

Use PING

Most TCP/IP transports attempt to use the DNS. DNS is a mechanism used to translate the host name specified in the TNSNAMES.ORA file into the host internet address (IP). If a DNS is present on your network and the TCP/IP vendor supports DNS, the host name is successfully translated to the host address. The host IP address can be determined by using the Control Panel's Network utility to access DNS information.

Depending on your vendor, workstation configuration, and network configuration, your TCP/IP software can also use a SYSTEMROOT\SYSTEM32\DRIVERS\ETC\HOSTS file to map host names to Internet addresses if DNS is not detected or supported.

If DNS and the HOSTS file are unable to resolve the host name during a remote database connection, the following error message appears:

ORA-12545: TNS: name lookup failure

If your network administrator cannot resolve the problem, the solution to this error message is to go around DNS and the HOSTS file by modifying the (HOST = SERVER_NAME) section of the TNSNAMES.ORA, so SERVER_NAME is changed to the IP address of the server.

The following sections explain how to determine the server's IP address and verify that DNS and the HOSTS file are working correctly.

Determine the Server's IP Address

If you are not using TCP/IP, go to "Verify Oracle Database Connections Using TNSPING" in this chapter.

To determine the server's TCP/IP internet address:

Note:   If you are not authorized for access on the server, ask your server administrator for assistance.

   

1. From the Control Panel window, double-click Network.

The Network window appears.

2. Choose the Protocols tab.

The Protocols view appears:


3. From the Protocol view, select the TCP/IP Protocol Adapter, and click Properties.

The Microsoft TCP/IP Properties dialog box appears with the IP Address view:


4. Obtain the IP address, and click Cancel to close the Microsoft TCP/IP Properties dialog box.
5. Click Cancel to close the Network window.
6. Continue to the next section, "Use PING".

Use PING

If you are using TCP/IP, PING allows you to determine if DNS or the HOSTS file are correctly set up and your network operating system is functioning correctly.

To use PING:

From the client, enter the following at the command prompt:

C:\> PING SERVER_NAME

where SERVER_NAME is the host name, alias, or Internet address of the server to which you are trying to connect.

If your network is functioning correctly, the following message appears:

Reply from SERVER_NAME: bytes=nn time=nnms

If there is a problem, this message appears:

Request timed out

Or:

Reply from SERVER_NAME: Destination host unreachable

The following is a partial list of reasons why a host is inaccessible:

• the server is not accessible through the network
• the remote host is not online
• the domain name server is not functioning
• a domain name server is not accessible through the network
• the server name does not exist in the HOSTS file

If PING returns an error message, ask your network administrator to help you resolve the problem. If the problem is not resolved, and you attempt to make a Net8 connection, you may receive one of the following error messages:

• ORA-12203: TNS: unable to connect to destination
• ORA-12535: TNS: Failure to redirect to destination
• ORA-12541: TNS: no listener

Verify Oracle Database Connections Using TNSPING

Use the TNSPING80 utility to determine whether or not you can reach the network listener service. TNSPING80, however, never actually connects with the network listener. A socket is never created and opened. TNSPING80 only checks to ascertain that a network listener is present on the server side.

When you connect to a network listener using TNSPING80, an estimate of the round trip time in milliseconds appears. If TNSPING80 fails, a network error message appears without the resource use of a database connection.

To use TNSPING80:

From the client, enter:

TNSPING80 SERVICE_NAME COUNT 

where SERVICE_NAME is the service name (defined in the TNSNAMES.ORA) you created in "Using the Local Naming Method" of this chapter and COUNT is the number of times the program attempts to reach the server. COUNT is optional.

The output looks like:

TNS Ping Utility for 32-bit Windows: Version 8.0.4.0.0 - Production on 27 OCT-97 
20:20:33

Copyright, 1997(c) Oracle Corporation 1997. All rights reserved.

Attempting to contact (ADDRESS=(COMMUNITY=tcp.world)(PROTOCOL=TCP)(Host=host_
name)(Port=1521))
OK (60 msec)

Verify Oracle Database Connection Using Oracle Net8 Easy Config

Note:   The instructions below only apply if you have configured using the local naming method. If you have not configured with the local naming method, connect to the database using the instructions in "Step 5: Connect to the Database" of Chapter 7, "Connecting To a Database".

   

Use the Oracle Net8 Easy Config application to determine whether or not you can reach the network listener service.

To verify connectivity for a client machine:

1. Choose Start > Programs > Oracle for Windows NT - HOME_NAME > Net8 Easy Configuration Tool.

Oracle Net8 Easy Config starts.

2. Click Test.
3. Select a service name from the Existing Services list box you created in "Using the Local Naming Method" in this chapter.
4. Click Next.

The Connection Test page appears:


5. Enter a valid Username and Password, such as SYSTEM and MANAGER, for the database you want to connect to, and click Test.

The status of the test appears in the field below the Test button. A successful test displays the following message:

The connection test was successful.

6. Click Done when the test is complete.

The final page appears.

7. Click Finish to save your configuration and dismiss the Net8 Easy Configuration Tool.

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