Multi Router Traffic Grapher

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MRTG

Developer:	Tobi Oetiker
Latest release:	2.14.6 / September 6, 2006
OS:	Cross-platform
Use:	Bandwidth monitor
License:	GNU General Public License
Website:	oss.oetiker.ch/mrtg/

The Multi Router Traffic Grapher or just simply MRTG is free software for monitoring the traffic load on network links. It allows the user to see traffic load on a network over time in graphical form.

MRTG is written in Perl and works on Unix/Linux as well as Windows and even Netware systems. MRTG is free software licensed under the GNU GPL.

It was originally developed by Tobias Oetiker and Dave Rand to monitor router traffic, but has developed into a tool that can create graphs and statistics for almost anything.

1 How does it work?
2 Features
3 See also
4 External links

[edit] How does it work?

MRTG uses the Simple Network Management Protocol (SNMP) to send requests with two object identifiers (OIDs) to a device. The device, which must be SNMP-enabled, will have a management information base (MIBs) to lookup the OID's specified. After collecting the information it will send back the raw data encapsulated in an SNMP protocol. MRTG records this data in a log on the client along with previously recorded data for the device. The software then creates an HTML document from the logs, containing a list of graphs detailing traffic for the selected device.

[edit] Features

Measures 2 values (I for Input, O for Output) per target.
Gets its data via an SNMP agent, or through the output of a command line.
Typically collects data every five minutes (it can be configured to collect data less frequently).
Creates an HTML page per target that features 4 graphs (GIF or PNG images).
Results are plotted vs time into day, week, month and year graphs, with the I plotted as a full green area, and the O as a blue line.
Automatically scales the Y axis of the graphs to show the most detail.
Adds calculated Max, Average and Current values for both I and O to the target's HTML page.
Can also send warning emails if targets have values above a certain threshold.

MRTG is freely available under the terms of the GNU General Public License. MRTG can be running on Windows, Linux, Unix, Mac OS and NetWare.

[edit] See also

Free software Portal

RRDtool - reimplementation of MRTG's graphing and logging features
Cacti - The Complete RRDtool-based graphing solution.
PRTG - Windows GUI implementation of MRTG's functionality (Freeware available)
Network traffic measurement - tools that help network administrators to track down the reasons for overloaded network uplinks
RANCID - software to monitor router/switch configuration changes
Smokeping - network latency measurement tool, using RRDtool.