Databases Reference
In-Depth Information
CHAPTER 29
■ ■ ■
TNS Listener IP Address
Binding and IP=FIRST
O
n systems that have more than one network adapter, the default behavior of the TNS
Listener is to accept connections from any network. In Oracle10
g
and subsequent releases
IP=FIRST
may be used to restrict incoming connections to the network in which the host
configured in
listener.ora
resides.
The
Oracle Database, Oracle Clusterware and Oracle Real Application Clusters Installation
Guide 10g Release 2 for AIX
contains an example TNS Listener configuration that makes use of
IP=FIRST
in the configuration file
listener.ora
, but does not explain its meaning. This option
is not documented in
Oracle Database Net Services Reference 10g Release 2
.
IP=FIRST
is docu-
mented in
Oracle Database Net Services Reference 11g Release 1
, yet the documentation is not
entirely correct.
1
The manual does not address all the implications of the parameter. Further-
more it is undocumented that the listener's behavior concerning the loopback adapter is also
influenced by
IP=FIRST
.
Introduction to IP Address Binding
Internet protocol network addresses may be classified into three functional categories:
Boot IP addresses
Common (non-boot) IP addresses
Service IP addresses
Each system in a network is identified by a unique host name. The IP address assigned to
such a unique host name is called the boot IP address. This IP address is bound to a network
adapter during the boot process. The unique host name of a system is returned by the command
hostname
on both UNIX and Windows. The host name thus returned maps to the boot IP address.
No additional software except the operating system itself is required for the availability of the
boot IP address. Common (non-boot) addresses are addresses used by adapters other than the
boot adapter (the adapter which was assigned the boot address). Of course, the latter adapters
1.
Among other things, the syntax of the example is wrong and the C language preprocessor macro
INADDR_ANY
is reproduced incorrectly.
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