The Multi Router Traffic Grapher (MRTG) is

free software Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribut ...

for monitoring and

measuring Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. In other words, measurement is a process of determining how large or small a physical quantity is as compared to ...

the traffic load on network links. It allows the user to see traffic load on a network over time in graphical form. 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. MRTG is written in

Perl Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language". Perl was developed ...

and can run on

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Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

Unix Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

Mac OS Mac operating systems were developed by Apple Inc. in a succession of two major series. In 1984, Apple debuted the operating system that is now known as the classic Mac OS with its release of the original Macintosh System Software. The system ...

and

NetWare NetWare is a discontinued computer network operating system developed by Novell, Inc. It initially used cooperative multitasking to run various services on a personal computer, using the IPX network protocol. The final update release was ver ...

How it works

SNMP

MRTG uses the

Simple Network Management Protocol Simple Network Management Protocol (SNMP) is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. Devices that typically su ...

(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 A management information base (MIB) is a database used for managing the entities in a communication network. Most often associated with the Simple Network Management Protocol (SNMP), the term is also used more generically in contexts such as in ...

(MIB) to look up the OIDs 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 Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets ( ...

document from the logs, containing a list of graphs detailing traffic for the selected devices in the server.

Script output

Alternatively, MRTG can be configured to run a script or command, and parse its output for counter values. The MRTG website contains a large library of external scripts to enable monitoring of SQL database statistics, firewall rules, CPU fan RPMs, or virtually any integer-value data.

Features

* Measures two values (I for Input, O for Output) per target. * Gets its data via an

SNMP Simple Network Management Protocol (SNMP) is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. Devices that typically su ...

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

page per target that features four graphs (

GIF The Graphics Interchange Format (GIF; or , ) is a Raster graphics, bitmap Image file formats, image format that was developed by a team at the online services provider CompuServe led by American computer scientist Steve Wilhite and released ...

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.

References

External links