Network Configuration Files - Linux


All network communications occur between configured softwareinterfaces and physical networking devices connected to the system.

The configuration files for network interfaces are located in the /etc/sysconfig/network-scripts/directory. The scripts used to activate and deactivate these network interfaces are also located here. 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:

  1. Interface configuration files

  2. Interface control scripts

  3. Network function files

The files in each of these categories work together to enable various network devices.

Primary Network Configuration Files/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 ( as localhost.localdomain. For more information, refer to the hosts man page.


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.


This file specifies routing and host information for all network interfaces.


For each network interface, there is a corresponding interface configuration script. Each of these files provide information specific to a particular network interface.