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 Community 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 "/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 "Interface Configuration Files" for more information on this type of file and the directives it accepts.

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 Network Configuration