refer here :
http://www.cyberciti.biz/nixcraft/linux/docs/uniqlinuxfeatures/mrtg/mrtg_references.php

Basically , you need to properly setup the snmpd..
then test will snmp walk…
then only setup mrtg to parse the data and generate output
peridocally..

continue reading.....

Sometime we got more than one network interface..
let say one Ethernet Card and one wifi cards..
this will show you how to combine this into one.. and
get better throughout speed.

continue reading.....

first enable kernel rq interrupter.
for permanent one go add this line into /etc/sysctl.conf
vi /etc/sysctl.conf
add
kernel.sysrq=1
or else.. for this session only.
just
echo 1 > /proc/sys/kernel/sysrq
.. then..
triggerring system crash..
echo ‘c’ > /proc/sysrq-trigger
fuyoo….

continue reading.....