Step 1 : install vnstat

yum install vnstat

Step 2: Initialize database

vnstat -u -i eth0

Step 3: Schedule Cron , Edit /etc/cron.d/vnstat

*/5 * * * * root /usr/sbin/vnstat.cron

Frontend

Download : http://www.sqweek.com/sqweek/files/vnstat_php_frontend-1.5.1.tar.gz

extract file upload to ftp server and edit config.php

$language = 'en';
$iface_list = array('eth0', 'sixxs');
$iface_title['eth0'] = 'Public Interface';
$vnstat_bin = '/usr/bin/vnstat';