All language subtitles for [SubtitleTools.com] Networking Configuration Files - Learning Oracle 12c [Video]

In this lesson, we want
to discuss the network

configuration files that are
used in controlling an Oracle

network setup.

So Oracle Net is
controlled really

by three configuration files.

Before we look at those,
we need to remember

that there are four basic
pieces of information that

will establish a connection--
particularly to a database.

The first thing we have to know
is the hostname, or IP address.

So again, this is a remote
connection coming in,

so we need to know what the name
of the host on our network is,

or its IP address.

We also need to know the
port that the listener is

running on.

So the listener process listens
for incoming connections

and is going to use
a port on the server

that the database
is installed on.

And that port, by
default, is 1521,

although you can create
listeners with different ports

as well.

The third thing we need
to know is the protocol.

And normally, this is
going to be TCP/IP,

but Oracle does support some
other protocols as well,

so that needs to be specified.

And the fourth
piece of information

that we need to
establish a connection

is the name of the database.

So that's either the SID--

System Identifier--
or the SERVICE_NAME.

The SERVICE_NAME
basically is an alias

given for network purposes
to a particular database.

So the three main
configuration files

that we use in configuring
an Oracle Database Networking

stack are found in
the Oracle Home.

So here we are in the
Oracle base directory.

So let's proceed
to the Oracle Home.

Here in the Oracle Home, we
have a directory called Network.

Within that directory is
a directory called Admin.

And here are our three basic
network configuration files.

So the first is
the TNSNAMES.ORA,

and that's client side
connection information.

So everything that a
client needs in order

to connect to an Oracle database
is found in the TNSNAMES.ORA.

So let's open a TNSNAMES.ORA,
and let's focus on this section

right here.

So here we have an
alias to the database.

So oftentimes, this is the
same name as the database,

but it can be anything.

It can be your name or
my name or whatever,

but this is the name
that we'll use when we

try to connect to the database.

So the four things we need--

first, PROTOCOL = TCP--

and that stands for TCP/IP.

Then the HOST.

So here we have the IP
address of the host.

The PORT-- the
listener port is 1521--

and then the SERVICE_NAME,
or SID, is orcl.

So the four things
that we need--

PROTOCOL, HOST, PORT, and
SID, or SERVICE_NAME--

are all in this entry
in the TNSNAMES.ORA.

So this means that if we
attempt to connect at orcl,

this is the information that it
uses to resolve that and decide

where are we attempting to go?

The second network configuration
file is the LISTENER.ORA.

So the LISTENER.ORA has all
of the server-side connection

information.

So this file would actually be
on the database server itself,

and it'll have all
the information

that it needs for the listener
to function and adequately

receive incoming connections.

So here, in this network admin
directory, is the LISTENER.ORA.

We'll focus on this
section right here.

Notice that the establishment
of an address where

it says PROTOCOL = TCP, HOST,
and here's the IP address,

and PORT--

1521.

So this is essentially
the information

that the listener uses to
develop those new connections

as they come in.

So the listener uses
this information

for incoming connections.

And lastly, we had
the SQLNET.ORA.

These are parameters
that can apply

to both listeners and
incoming connections,

and so there are a number
of different parameters

that can go in the SQLNET.ORA,
but it's actually very common

for there to be very
few or even none.

And in some cases, databases
operate without a SQLNET.ORA

file at all.

We'll take a look at ours.

And so it has a
parameter in here called

SQLNET.AUTHETICATION_SERVICES
= (NTS).

So this is a line that
you would frequently

see on databases
running on Windows,

and it just has to deal with
the Windows NT Authentication

services.

So those are the three
network configuration

files that are involved.

They are essentially
set up whenever you do

an installation of a database.

The only exception
would generally

be the TNSNAMES.ORA on
a machine that actually

doesn't host a database.