Chapter 8. Network Interfaces
Under Red Hat Enterprise Linux, all network communications occur between configured software
interfaces and physical networking
devices connected to the system.
The configuration files for network interfaces, and the scripts used to
activate and deactivate them, are located in the
/etc/sysconfig/network-scripts/ directory. Although
the number and type of interface files can differ from system to system,
there are three categories of files that exist in this directory:
The files in each of these categories work together to enable various
network devices.
This chapter explores the relationship between these files and how they
are used.
Before delving into the interface configuration files, let us first
itemize the primary configuration files used in network
configuration. Understanding the role these files play in setting up the
network stack can be helpful when customizing a Red Hat Enterprise Linux system.
The primary network configuration files are as follows:
/etc/hosts — The main purpose of this
file is to resolve hostnames that cannot be resolved any other way. It
can also be used to resolve hostnames on small networks with no DNS
server. Regardless of the type of network the computer is on, this
file should contain a line specifying the IP address of the loopback
device (127.0.0.1) as
localhost.localdomain. For more information, refer
to the hosts man page.
/etc/resolv.conf — This file
specifies the IP addresses of DNS servers and the search
domain. Unless configured to do otherwise, the network
initialization scripts populate this file. For more information about
this file, refer to the resolv.conf man page.
/etc/sysconfig/network — Specifies
routing and host information for all network interfaces. For more
information about this file and the directives it accepts, refer to Section 4.1.25 /etc/sysconfig/network.
/etc/sysconfig/network-scripts/ifcfg-<interface-name>
— For each network interface, there is a corresponding interface
configuration script. Each of these files provide information specific
to a particular network interface. Refer to Section 8.2 Interface Configuration Files for more information on this
type of file and the directives it accepts.
 | Caution |
|---|
| | The /etc/sysconfig/networking/ directory is used
by the Network Administration Tool
(system-config-network) and its contents should not
be edited manually. In addition, any use of the
Network Administration Tool, even launching the
application, will override any directives previously set in
/etc/sysconfig/network-scripts. Using only one
method for network configuration is strongly encouraged, due to the
risk of configuration deletion.
For more information about configuring network interfaces using the
Network Administration Tool, refer to the chapter
titled Network Configuration in the
Red Hat Enterprise Linux System Administration Guide.
|
