MRTG with FreeBSD and a Cisco Router

It doesn't get much easier than this. I wanted to add the Multi Router Traffic Grapher (MRTG) to my NSM tool collection. Based on the instructions provided by Open Source Network Administration and Cisco, here's how I did it. bourque is the name of my FreeBSD 4.9 REL NSM sensor and gill.taosecurity.com is my Cisco router.

First I enabled the SNMP server on the router. Replace 'public' and 'private' with other community strings, like I did. (These are examples.)

gill(config)#snmp-server community public RO
gill(config)#snmp-server community private RW

Make sure you set up an access list on interfaces where you don't want people accessing the SNMP service on your router:

access-list 101 deny   udp any any eq snmp log

Next install an Apache Web server on the system which will hold MRTG's output:

bourque# pkg_add -r ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/
packages-4-stable/All/apache+mod_ssl-1.3.29+2.8.16.tgz
Fetching ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/
packages-4-stable/All/apache+mod_ssl-1.3.29+2.8.16.tgz... Done.
Fetching ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/
packages-4-stable/All/mm-1.3.0.tgz... Done.
bourque# apachectl start

Next install MRTG:

bourque# pkg_add -r ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/
packages-4.9-release/All/mrtg-2.9.29_3,1.tgz
Fetching ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/
packages-4.9-release/All/mrtg-2.9.29_3,1.tgz... Done.
Fetching ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/
packages-4.9-release/All/p5-SNMP_Session-0.95.tgz... Done.

Now configure MRTG:

bourque# mkdir /usr/local/www/data/mrtg
bourque# cfgmaker --global 'WorkDir: /usr/local/www/data/mrtg'
 --global 'Options[_]: bits' --global 'IconDir: icons'
 --snmp-options=:::::2 --subdirs=HOSTNAME --ifref=ip
 --ifdesc=alias --output /usr/local/etc/mrtg/mrtg.cfg 
 public@gill.taosecurity.com

--base: Get Device Info on public@gill.taosecurity.com:::::2
--base: Vendor Id: cisco
--base: Populating confcache
...edited output...

mkdir /usr/local/www/data/mrtg/icons
cp /usr/local/share/mrtg/* /usr/local/www/data/mrtg/icons/

Now start MRTG:

bourque# mrtg /usr/local/etc/mrtg/mrtg.cfg
WARNING: /usr/local/www/data/mrtg/gill.taosecurity.com/
 did not exist I will create it now
...ignore the warnings; these are normal for initial start-up...

Create an index page for the Web server and add an entry in cron to periodically collect MRTG data:

bourque# indexmaker --output /usr/local/www/data/mrtg/index.html
 --columns=1 /usr/local/etc/mrtg/mrtg.cfg

bourque# crontab -l
*/5 * * * * /usr/local/bin/mrtg /usr/local/etc/mrtg/mrtg.cfg
 --logging /var/log/mrtg.log

You'll want to add the following link for each router name so MRTG can find its icons:

ln -s /usr/local/www/data/mrtg/icons/
 /usr/local/www/data/mrtg/gill.taosecurity.com/icons

When you're done you'll see graphs like this when you visit http://sensor/mrtg/index.html. Notice there's only a little bit of data at the far left side, as the system's only been awake for a few minutes.

That's all you need for a basic install. Notice I'm accessing the sensor using HTTP. I could enable HTTPS and access the sensor using that method. Also, be careful running a Web server on your NSM appliance. Lock down who can access it.

Popular posts from this blog

Zeek in Action Videos

Image
This is a quick note to point blog readers to my Zeek in Action YouTube video series for the Zeek network security monitoring project .  Each video addresses a topic that I think might be of interest to people trying to understand their network using Zeek and adjacent tools and approaches, like Suricata, Wireshark, and so on.  I am especially pleased with Video 6 on monitoring wireless networks . It took me several weeks to research material for this video. I had to buy new hardware and experiment with a Linux distro that I had not used before -- Parrot .  Please like and subscribe, and let me know if there is a topic you think might make a good video.
Read more

MITRE ATT&CK Tactics Are Not Tactics

Image
Just what are "tactics"? Introduction MITRE ATT&CK  is a great resource, but something about it has bothered me since I first heard about it several years ago. It's a minor point, but I wanted to document it in case it confuses anyone else. The MITRE ATT&CK Design and Philosophy document from March 2020 says the following: At a high-level, ATT&CK is a behavioral model that consists of the following core components: • Tactics, denoting short-term, tactical adversary goals during an attack; • Techniques, describing the means by which adversaries achieve tactical goals; • Sub-techniques, describing more specific means by which adversaries achieve tactical goals at a lower level than techniques; and • Documented adversary usage of techniques, their procedures, and other metadata. My concern is with MITRE's definition of "tactics" as "short-term, tactical adversary goals during an attack," which is oddly recursive. The key word in the tacti...
Read more

New Book! The Best of TaoSecurity Blog, Volume 4

Image
  I've completed the TaoSecurity Blog book series . The new book is  The Best of TaoSecurity Blog, Volume 4: Beyond the Blog with Articles, Testimony, and Scholarship .  It's available now for Kindle , and I'm working on the print edition.  I'm running a 50% off promo on Volumes 1-3 on Kindle through midnight 20 April. Take advantage before the prices go back up. I described the new title thus: Go beyond TaoSecurity Blog with this new volume from author Richard Bejtlich. In the first three volumes of the series, Mr. Bejtlich selected and republished the very best entries from 18 years of writing and over 18 million blog views, along with commentaries and additional material.  In this title, Mr. Bejtlich collects material that has not been published elsewhere, including articles that are no longer available or are stored in assorted digital or physical archives. Volume 4 offers early white papers that Mr. Bejtlich wrote as a network defender, either for technica...
Read more