NAME

       mrtg - What is MRTG ?

DESCRIPTION

       The Multi Router Traffic Grapher (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.

       Go to http://oss.oetiker.ch/mrtg for all the details about mrtg.

HIGHLIGHTS

       Portable
           MRTG works on most UNIX platforms and Windows NT.

       Perl
           MRTG is written in Perl and comes with full source.

       Portable SNMP
           MRTG  Uses  a  highly portable SNMP implementation written entirely in Perl (thanks to Simon Leinen).
           There is no need to install any external SNMP package.

       SNMPv2c support
           MRTG can read the new SNMPv2c 64bit counters. No more counter wrapping.

       Reliable Interface Identification
           Router interfaces can be identified by IP address, description and ethernet address  in  addition  to
           the normal interface number.

       Constant size Logfiles
           MRTG's logfiles do NOT grow thanks to the use of a unique data consolidation algorithm.

       Automatic Configuration
           MRTG comes with a set of configuration tools which make configuration and setup very simple.

       Performance
           Time critical routines are written in C (thanks to the initiative of Dave Rand my Co-Author).

       GIF free Graphics
           Graphics are generated directly in PNG format using the GD library by Thomas Boutell.

       Customizability
           The look of the webpages produced by MRTG is highly configurable.

       RRDtool
           MRTG has built-in hooks for using RRDtool. If you are strapped for performance this may help.

DETAILS

       MRTG  consists of a Perl script which uses SNMP to read the traffic counters of your routers and a fast C
       program which logs the traffic data  and  creates  beautiful  graphs  representing  the  traffic  on  the
       monitored network connection. These graphs are embedded into webpages which can be viewed from any modern
       Web-browser.

       In addition to a detailed daily view, MRTG also creates visual representations of the traffic seen during
       the  last seven days, the last five weeks and the last twelve months. This is possible because MRTG keeps
       a log of all the data it has pulled from the router. This log is automatically consolidated  so  that  it
       does  not grow over time, but still contains all the relevant data for all the traffic seen over the last
       two years.  This is all performed in an efficient manner.  Therefore you can monitor 200 or more  network
       links from any halfway decent UNIX box.

       MRTG  is  not  limited  to  monitoring  traffic, though.  It is possible to monitor any SNMP variable you
       choose. You can even use an external program to gather the data  which  should  be  monitored  via  MRTG.
       People  are  using  MRTG,  to  monitor things such as System Load, Login Sessions, Modem availability and
       more. MRTG even allows you to accumulate two or more data sources into a single graph.

HISTORY

       In 1994 I was working at a site where we had one 64kbit line to the outside world.  Obviously,  everybody
       was interested in knowing how the link was performing. So I wrote a quick hack which created a constantly
       updated  graph on the web that showed the traffic load on our Internet link. This eventually evolved into
       a rather configurable Perl script called MRTG-1.0 which I released in spring 1995. After a few updates, I
       left my job at DMU to start work at the Swiss Federal Institute of Technology. Due to lack of time I  had
       to  put MRTG aside. One day in January of 1996, I received email from Dave Rand asking if I had any ideas
       why MRTG was so slow. Actually, I did. MRTG's programming was not  very  efficient  and  it  was  written
       entirely  in  Perl.  After a week or so, Dave wrote back to me and said he had tried what I had suggested
       for improving MRTG's speed. Since the changes did not help much, he had  decided  to  rewrite  the  time-
       critical  sections of MRTG in C. The code was attached to his email. His tool increased the speed of MRTG
       by a factor of 40! This got me out of my 'MRTG ignorance' and I started to spend my spare time developing
       of MRTG-2.

       Soon after MRTG-2 development had begun I started to give beta copies to interested parties. In return  I
       got  many feature patches, a lot of user feedback and bug fixes. The product you are getting now wouldn't
       be in this state if it hadn't been for the great contributions  and  support  I  received  from  of  many
       people.  I  would like to take this opportunity to thank them all. (See the files CHANGES for a long list
       of folk people who helped to make MRTG what it is today.)

Command-line

       Mrtg is also the name of the script you  have  to  run  to  poll  data  and  generate  the  graphs.  Most
       configuration is set through the configuration file; some command-line options exist all the same.

       --user username  and --group groupname
           Run as the given user and/or group. (Unix Only)

       --lock-file filename
           Use an alternate lock-file (the default is to use the configuration-file appended with "_l").

       --confcache-file filename
           Use an alternate confcache-file (the default is to use the configuration-file appended with ".ok")

       --logging filename|eventlog
           If  this is set to writable filename, all output from mrtg (warnings, debug messages, errors) will go
           to filename. If you are running on Win32 you can specify eventlog instead of a  filename  which  will
           send all error to the windows event log.

           NOTE:Note,  there  is no Message DLL for mrtg. This has the side effect that the windows event logger
           will display a nice message with every entry in the event log, complaining about the fact  that  mrtg
           has no message dll. If any of the Windows folks want to contribute one, they are welcome.

       --daemon
           Put MRTG into the background, running as a daemon. This works the same way as the config file option,
           but the switch is required for proper FHS operation (because /var/run is writable only by root)

       --fhs
           Configure  all  mrtg  paths  to  conform to the FHS specification <http://www.pathname.com/fhs/>. The
           following default values are assumed:

            confcachefile - /var/lib/mrtg/mrtg.ok
            pid-file      - /run/mrtg/mrtg.pid
            lock-file     - /var/lock/mrtg/mrtg.lck
            log-file      - /var/log/mrtg/mrtg.log

       --check
           Only check the cfg file for errors. Do not do anything.

       --pid-file=s
           Define the name and path of the pid file for mrtg running as a daemon

       --log-only
           Only update the logfile, do not produce graphics or html pages

       --debug=s
           Enable debug options. The argument of the debug option is a comma separated list of debug values:

            cfg  - watch the config file reading
            dir  - directory mangeling
            base - basic program flow
            tarp - target parser
            snpo - snmp polling
            fork - forking view
            time - some timing info
            log  - logging of data via rateup or rrdtool

           Example:

            --debug="cfg,snpo"

READ ON

       Learn more about MRTG by going to the mrtg home page on: http://oss.oetiker.ch/mrtg

AUTHOR

       Tobias Oetiker <tobi@oetiker.ch> and many contributors

2.17.10                                            2022-01-19                                            MRTG(1)