4 Protocol Address Configuration

Learn how to configure connections for Oracle Database instances and clients.

A network object is identified by a protocol address. When a connection is made, the client and the receiver of the request (listener or Oracle Connection Manager) are configured with identical protocol addresses. The client uses this address to send the connection request to a particular network object location, and the recipient "listens" for requests on this address, and grants a connection based on its address information matching the client information.

• Protocol Addresses
  The protocol address is comprised of ADDRESS and ADDRESS_LIST elements.
• Protocol Parameters
  The listener and Oracle Connection Manager are identified by protocol addresses.
• Recommended Port Numbers
  Oracle recommends that you use the default port numbers for client and Oracle Connection Manager connections.
• Port Number Limitations
  Understand limitations for port numbers. If it is necessary to configure a listener to use a system port number (in the 1 to 1024 range), then use the procedure described here to configure the listener.

4.1 Protocol Addresses

The protocol address is comprised of ADDRESS and ADDRESS_LIST elements.

• ADDRESS
  The ADDRESS networking parameter specifies the protocol address under the ADDRESS_LIST or DESCRIPTION parameter.
• ADDRESS_LIST
  The ADDRESS_LIST networking parameter specifies the number of protocol addresses sharing common characteristics.

4.1.1 ADDRESS

The ADDRESS networking parameter specifies the protocol address under the ADDRESS_LIST or DESCRIPTION parameter.

Purpose

To define a protocol address.

Usage Notes

Put this parameter under an ADDRESS_LIST or DESCRIPTION parameter. A DESCRIPTION is used in a tnsnames.ora or a listener.ora file.

Example

(ADDRESS=
 (PROTOCOL=tcp)
 (HOST=sales-server)
 (PORT=1521))

4.1.2 ADDRESS_LIST

The ADDRESS_LIST networking parameter specifies the number of protocol addresses sharing common characteristics.

Purpose

To define a list of protocol addresses that share common characteristics.

Usage Notes

This parameter is not mandatory when specifying multiple addresses.

Example

(ADDRESS_LIST=
  (LOAD_BALANCE=on)
  (ADDRESS=
   (PROTOCOL=tcp)
   (HOST=sales-server)
   (PORT=1521))
  (ADDRESS=
   (PROTOCOL=tcp)
   (HOST=hr-server)
   (PORT=1521)))

4.2 Protocol Parameters

The listener and Oracle Connection Manager are identified by protocol addresses.

The following table lists the parameters used by the Oracle protocol support:

Table 4-1 Protocol-Specific Parameters

Protocol	Parameter	Description
IPC	PROTOCOL	Specify ipc as the value.
IPC	KEYPATH	On UNIX variants, IPC protocol uses the UNIX domain socket and this socket creates an internal file for client/server communication. The parameter keypath specifies the location where this file is created. If keypath is used, then use the same value of version greater than 18 on the client and listener sides.
IPC	KEY	Specify a unique name for the service. Oracle recommends using the service name or the Oracle system identifier (SID) of the service. Example: (PROTOCOL=ipc)(KEY=sales)
Named Pipes	PROTOCOL	Specify nmp as the value.
Named Pipes	SERVER	Specify the name of the Oracle server.
Named Pipes	PIPE	Specify the pipe name used to connect to the database server. This is the same PIPE keyword specified on server with Named Pipes. This name can be any name. Example: (PROTOCOL=nmp)(SERVER=sales)(PIPE=dbpipe0)
SDP	PROTOCOL	Specify sdp as the value.
SDP	HOST	Specify the host name or IP address of the computer.
SDP	PORT	Specify the listening port number. Example: (PROTOCOL=sdp)(HOST=sales-server)(PORT=1521) (PROTOCOL=sdp)(HOST=192.0.2.204)(PORT=1521)
TCP/IP	PROTOCOL	Specify tcp as the value.
TCP/IP	HOST	Specify the host name or IP address of the computer.
TCP/IP	PORT	Specify the listening port number. Example: (PROTOCOL=tcp)(HOST=sales-server)(PORT=1521) (PROTOCOL=tcp)(HOST=192.0.2.204)(PORT=1521)
TCP/IP with TLS	PROTOCOL	Specify tcps as the value.
TCP/IP with TLS	HOST	Specify the host name or IP address of the computer.
TCP/IP with TLS	PORT	Specify the listening port number. Example: (PROTOCOL=tcps)(HOST=sales-server)(PORT=2484) (PROTOCOL=tcps)(HOST=192.0.2.204)(PORT=2484)
Exadirect	PROTOCOL	Specify exadirect as the value.
Exadirect	HOST	Specify the IP address of the InfiBand interface.
Exadirect	PORT	Specify the listening port number. Example: (PROTOCOL=exadirect)(HOST=sales-server)(PORT=2484) (PROTOCOL=tcps)(HOST=192.0.2.204)(PORT=1522)
Websocket	PROTOCOL	Specify ws as the value; use this protocol only to serve as web server backend database server.
Websocket	HOST	Specify the host name or IP address of the computer.
Websocket	PORT	Specify the listening port number. Example: (protocol=ws)(host=sales-server)(port=1524)
Secure Websocket	PROTOCOL	Specify ws as the value; use this protocol on the client side to connect to a webserver with websocket protocol support. The web server should be configured to make a websocket connection to the database listener. Wallet should be configured in sqlnet.ora. Use SQLNET.URI for mapping on web server.
Secure Websocket	HOST	Specify the host name or IP address of the web server with websocket support.
Secure Websocket	PORT	Specify the listening port number. Example: (protocol=wss)(host=sales-server)(port=1524)

4.3 Recommended Port Numbers

Oracle recommends that you use the default port numbers for client and Oracle Connection Manager connections.

Table 4-2 Recommended Port Numbers

Port	Description
1521	Default listening port for client connections to the listener. This port number can change to the officially registered port number of 2483 for TCP/IP, and 2484 for TCP/IP with TLS.
1521	Default and officially registered listening port for client connections to Oracle Connection Manager.
1830	Default and officially registered listening port for administrative commands to Oracle Connection Manager.

4.4 Port Number Limitations

Understand limitations for port numbers. If it is necessary to configure a listener to use a system port number (in the 1 to 1024 range), then use the procedure described here to configure the listener.

Oracle allows port numbers from 1 to 65535. However, the port numbers below 1024 (the well-known ports or system ports) are typically reserved. Normally, only privileged processes can listen for TCP connections on ports below 1024.

If you need to configure a listener to listen on a port number less than 1024, then complete the following procedure:

Note:

This procedure is a guideline. Your operating system can require a different procedure.

1. Use Oracle Net Configuration Assistant or Oracle Net Manager to configure the listener with protocol addresses and other configuration parameters.

2. Log in as the root user on the machine that has the listener.

3. Set file ownership and access permissions for the listener executable (tnslsnr) and the dependent shared libraries, so that these files can be modified only by the root user.

4. Starting with the root directory, ensure that the permissions of the individual directories found in the path names to these files share the same ownership and access permissions.

5. Start the listener as the root user.

6. Enter the following command at the system prompt:

   tnslsnr listener_name -user user -group group
   

   In the preceding command, the following options are used:

   Table 4-3 tnslsnr Utility Options

   Options	Description
   listener_name	Specify the name of the listener that you want to configure. If omitted, then the default name LISTENER is used.
   user	Specify the user whose privileges you want the listener to use when super user (root) privileges are not needed. After performing the privileged operations, the listener gives up root privileges irreversibly.
   group	Specify the group whose privileges you want the listener to use when super user (root) group privileges are not needed. After performing the privileged operations, the listener gives up root group privileges irreversibly.

   During this step, the listener changes from root to the user and group privileges that you specify. All operations are done with the specified user and group privileges, except the system calls necessary to listen on configured endpoints. The listener reverts to the root user to listen on reserved addresses, such as TCP ports less than 1024.

   After the listener starts listening on all of its endpoints configured in the listener.ora file, it switches to the specified user and group irreversibly. At that point. the listener gives up the root privilege that it initially had. The -user and -group command line arguments only accept user and group identifiers specified in numeric form.

   For example, to run a listener called mylsnr with root privileges, and to have it use privileges of the Oracle user with the user identifier (UID) of 37555, and with OSDBA group dba membership, with a group identifier (GID) of 16, enter the following command at the operating system prompt:

   tnslsnr mylsnr -user 37555 -group 16
   

7. After the listener starts, you can administer it with the Listener Control utility.

   Caution:

   • Oracle recommends that the user under whose privileges the listener process runs is the oracle user, or a similarly privileged user with whose privileges the listener process normally runs on the operating system.

   • Do not leave the listener process running as the root user. Running processes as the super user is a security vulnerability.