The primary network configuration files are as follows:
/etc/hosts — The main purpose of this file is to resolve hostnames that cannot be resolved in any other way. This file should contain a line specifying the IP address of the loopback device (127.0.0.1) as localhost.localdomain.
/etc/resolv.conf — This file specifies the IP addresses of the DNS servers.
/etc/sysconfig/network — Specifies routing and host information for all network interfaces.
/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.