14.1. Network Configuration Files

14.1. Network Configuration Files

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

This file specifies routing and host information for all network interfaces. For more information about this file and the directives it accepts, refer to Section 28.1.21, “/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 14.2, “Interface Configuration Files” for more information on this type of file and the directives it accepts.

Warning

The /etc/sysconfig/networking/ directory is used by the Network Administration Tool (system-config-network) and its contents should not be edited manually. 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 Chapter 15, Network Configuration


Note: This documentation is provided {and copyrighted} by Red Hat®, Inc. and is released via the Open Publication License. The copyright holder has added the further requirement that Distribution of substantively modified versions of this document is prohibited without the explicit permission of the copyright holder. The CentOS project redistributes these original works (in their unmodified form) as a reference for CentOS-5 because CentOS-5 is built from publicly available, open source SRPMS. The documentation is unmodified to be compliant with upstream distribution policy. Neither CentOS-5 nor the CentOS Project are in any way affiliated with or sponsored by Red Hat®, Inc.