/etc/yum.repos.d/

Any file created in /etc/yum.repos.d/ with .repo extension is a repository file for Yellowdog Updater Modified. The contents of the file should have a general format.

[test]               
name=Test
baseurl=file:///var/ftp/pub/Server
        ftp://192.168.1.254/pub/Server
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

You can add any number of repository on the same file with unique name field. 

/etc/resolve.conf

The DNS name server is defined on this file. Optionally you can define it to search the domain.

search localdomain
nameserver 192.168.2.2

/etc/sysconfig/network

This file defines the hostname of your computer.

NETWORKING=yes
NETWORKING_IPV6=no
HOSTNAME=localhost.localdomain