intERLab AIT March 2008

Network Management Workshop



In 12 Steps

1. Install MRTG

# apt-get install mrtg

2. Create the /etc/mrtg directory

$ sudo mkdir /etc/mrtg

3. Find out the SNMP Community String – 1nterl4b

4. Find the IP / name of the Device


- or one of the other routers and switches (,,,,

5. Run cfgmaker (the command below all on one line!)

# /usr/bin/cfgmaker --output=/etc/mrtg/router.mrtg --global 'workdir: /var/www/mrtg'

--global 'options[_]: growright,bits' 1nterl4b@10.10.?.?

Make the workdir if necessary:

# mkdir -p /var/www/mrtg/

6. View the mrtg configuration file created by cfgmaker, you can make changes and see the results, if you want (/etc/mrtg/router.mrtg)

7. Use indexmaker to create HTML files

# /usr/bin/indexmaker --output=/var/www/mrtg/device.html /etc/mrtg/router.mrtg

8. Run MRTG command (ignore the error and run 3 times)

# /usr/bin/mrtg /etc/mrtg/router.mrtg

9. put the above command in a script

# echo '/usr/bin/mrtg /etc/mrtg/router.mrtg' > /etc/mrtg/mrtgscript

# chmod +x /etc/mrtg/mrtgscript

NOTE: on systems with UTF-8 as the default locale, this will cause problems – you need to explicitly specify: 'env LANG=C /usr/bin/mrtg /etc/mrtg/router.mrtg' when running the script.

10. Edit the crontab and insert the command to be run every 5 minutes

# crontab -e

0-59/5 * * * * /etc/mrtg/mrtgscript

11. Load the browser through webserver


12. Go for Tea / come back and see if your graph is moving.


# apt-get install rrdtool

# apt-get install librrdp-perl

# apt-get install librrds-perl

Add in your MRTG Configuration file

# vi /etc/mrtg/router.mrtg

; add below Workdir

LogFormat: rrdtool

[ go to /var/www/mrtg/ and see how the .rrd files have been created]

What about graphs ?

1. Install mrtg-rrd

# apt-get install mrtg-rrd

# cd /usr/lib/cgi-bin

# ln -s mrtg-rrd.cgi 14all.cgi

2. rerun indexmaker

# /usr/bin/indexmaker --output=/var/www/mrtg/device.html /etc/mrtg/router.mrtg

3. Create /etc/mrtg-rrd.conf like this:

# echo '/etc/mrtg/router.mrtg' >/etc/mrtg-rrd.conf

4. Make /var/www/mrtg writeable for the Web server:

# chown www-data /var/www/mrtg

Look at the webpage (http://localhost/mrtg/router.html) again!