Multi Router Traffic Grapher

陳伯岡

Outline

• What is MRTG• Why MRTG• How MRTG work• Start you own MRTG• Reference• Exercise & Homework

What is MRTG

• Multi Router Traffic Grapher– The MRTG is a tool to monitor the traffic load on

network links. – MRTG generates HTML pages containing PNG

images which provide a LIVE visual representation of this traffic.

Why MRTG

• Monitoring your computer

• Why not other tools?– Cacti– Nagios– Zabbix– RRDtool

How MRTG work

mrtg.cfg/usr/bin/mrtg

.png .html.log

data

Gather by yourself

SNMPSimple Network

Management Protocol

Start you own MRTG

• Installation– yum install• mrtg• net-snmp*

• Run snmpd– service snmpd start– chkconfig snmpd on– snmpwalk -v 1 -c public “your IP addr” system• Ex: snmpwalk -v 1 -c public 10.20.10.140 system

Start you own MRTG (cont.)

• change configuration: /etc/snmp/snmpd.conf– rocommunity public– syslocation "318"– syscontact lilykoko@ncnu.info

• Restart snmpd

Start you own MRTG (cont.)

• cfgmaker --output=/var/www/mrtg/net/mrtg.cfg \public@10.20.10.140

• vi mrtg.cfg– WorkDir: /var/www/mrtg/net/– Options[local]: growright, bits– Language: BIG5– Target[local]:2:public@10.20.10.140– Title[local]:Netflow– MaxBytes[local]:12500000– PageTop[local]: <H1>Netstat Info on 10.20.10.140</H1>

• indexmaker --output=/var/www/mrtg/net/index.html \ /var/www/mrtg/net/mrtg.cfg

Start you own MRTG (cont.)

• crontab –e– */5 * * * * /usr/bin/mrtg /var/www/mrtg/net/mrtg.cfg

• Then you can check the MRTG through your httpd

Reference

• MRTG 官方網站– http://oss.oetiker.ch/mrtg/

• 鳥哥 MRTG– http://linux.vbird.org/linux_security/old/

04mrtg.php

Exercise & Homework

• Exercise1. 按照投影片的步驟，利用 SNMP 監測自己主機的網路

流量2. 利用自行抓取資料的方式，監測自己主機的 CPU 使用

率• Homework

1. 參考 http://oss.oetiker.ch/mrtg/doc/mrtg-reference.en.html 改變圖中線條的顏色

2. 發揮想像力，監測自己主機任意一項流量