1MRTG(1)                              mrtg                              MRTG(1)
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NAME

6       mrtg - What is MRTG ?
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DESCRIPTION

9       The Multi Router Traffic Grapher (MRTG) is a tool to monitor the
10       traffic load on network links.  MRTG generates HTML pages containing
11       PNG images which provide a LIVE visual representation of this traffic.
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13       Go to http://oss.oetiker.ch/mrtg for all the details about mrtg.
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HIGHLIGHTS

16       Portable
17           MRTG works on most UNIX platforms and Windows NT.
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19       Perl
20           MRTG is written in Perl and comes with full source.
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22       Portable SNMP
23           MRTG Uses a highly portable SNMP implementation written entirely in
24           Perl (thanks to Simon Leinen). There is no need to install any
25           external SNMP package.
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27       SNMPv2c support
28           MRTG can read the new SNMPv2c 64bit counters. No more counter
29           wrapping.
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31       Reliable Interface Identification
32           Router interfaces can be identified by IP address, description and
33           ethernet address in addition to the normal interface number.
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35       Constant size Logfiles
36           MRTG's logfiles do NOT grow thanks to the use of a unique data
37           consolidation algorithm.
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39       Automatic Configuration
40           MRTG comes with a set of configuration tools which make
41           configuration and setup very simple.
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43       Performance
44           Time critical routines are written in C (thanks to the initiative
45           of Dave Rand my Co-Author).
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47       GIF free Graphics
48           Graphics are generated directly in PNG format using the GD library
49           by Thomas Boutell.
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51       Customizability
52           The look of the webpages produced by MRTG is highly configurable.
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54       RRDtool
55           MRTG has built-in hooks for using RRDtool. If you are strapped for
56           performance this may help.
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DETAILS

59       MRTG consists of a Perl script which uses SNMP to read the traffic
60       counters of your routers and a fast C program which logs the traffic
61       data and creates beautiful graphs representing the traffic on the
62       monitored network connection. These graphs are embedded into webpages
63       which can be viewed from any modern Web-browser.
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65       In addition to a detailed daily view, MRTG also creates visual
66       representations of the traffic seen during the last seven days, the
67       last five weeks and the last twelve months. This is possible because
68       MRTG keeps a log of all the data it has pulled from the router. This
69       log is automatically consolidated so that it does not grow over time,
70       but still contains all the relevant data for all the traffic seen over
71       the last two years.  This is all performed in an efficient manner.
72       Therefore you can monitor 200 or more network links from any halfway
73       decent UNIX box.
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75       MRTG is not limited to monitoring traffic, though.  It is possible to
76       monitor any SNMP variable you choose. You can even use an external
77       program to gather the data which should be monitored via MRTG. People
78       are using MRTG, to monitor things such as System Load, Login Sessions,
79       Modem availability and more. MRTG even allows you to accumulate two or
80       more data sources into a single graph.
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HISTORY

83       In 1994 I was working at a site where we had one 64kbit line to the
84       outside world. Obviously, everybody was interested in knowing how the
85       link was performing. So I wrote a quick hack which created a constantly
86       updated graph on the web that showed the traffic load on our Internet
87       link. This eventually evolved into a rather configurable Perl script
88       called MRTG-1.0 which I released in spring 1995. After a few updates, I
89       left my job at DMU to start work at the Swiss Federal Institute of
90       Technology. Due to lack of time I had to put MRTG aside. One day in
91       January of 1996, I received email from Dave Rand asking if I had any
92       ideas why MRTG was so slow. Actually, I did. MRTG's programming was not
93       very efficient and it was written entirely in Perl. After a week or so,
94       Dave wrote back to me and said he had tried what I had suggested for
95       improving MRTG's speed. Since the changes did not help much, he had
96       decided to rewrite the time-critical sections of MRTG in C. The code
97       was attached to his email. His tool increased the speed of MRTG by a
98       factor of 40! This got me out of my 'MRTG ignorance' and I started to
99       spend my spare time developing of MRTG-2.
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101       Soon after MRTG-2 development had begun I started to give beta copies
102       to interested parties. In return I got many feature patches, a lot of
103       user feedback and bug fixes. The product you are getting now wouldn't
104       be in this state if it hadn't been for the great contributions and
105       support I received from of many people. I would like to take this
106       opportunity to thank them all. (See the files CHANGES for a long list
107       of folk people who helped to make MRTG what it is today.)
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Command-line

110       Mrtg is also the name of the script you have to run to poll data and
111       generate the graphs. Most configuration is set through the
112       configuration file; some command-line options exist all the same.
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114       --user username  and --group groupname
115           Run as the given user and/or group. (Unix Only)
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117       --lock-file filename
118           Use an alternate lock-file (the default is to use the
119           configuration-file appended with "_l").
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121       --confcache-file filename
122           Use an alternate confcache-file (the default is to use the
123           configuration-file appended with ".ok")
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125       --logging filename|eventlog
126           If this is set to writable filename, all output from mrtg
127           (warnings, debug messages, errors) will go to filename. If you are
128           running on Win32 you can specify eventlog instead of a filename
129           which will send all error to the windows event log.
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131           NOTE:Note, there is no Message DLL for mrtg. This has the side
132           effect that the windows event logger will display a nice message
133           with every entry in the event log, complaing about the fact that
134           mrtg has no message dll. If any of the Windows folks want to
135           contribute one, they are welcome.
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137       --daemon
138           Put MRTG into the background, running as a daemon. This works the
139           same way as the config file option, but the switch is required for
140           proper FHS operation (because /var/run is writable only by root)
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142       --fhs
143           Configure all mrtg paths to conform to the FHS specification
144           <http://www.pathname.com/fhs/>. The following default values are
145           assumed:
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147            confcachefile - /var/cache/mrtg/mrtg.ok
148            pid-file      - /var/run/mrtg.pid
149            lock-file     - /var/cache/mrtg/mrtg.lck
150            log-file      - /var/log/mrtg.log
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152       --check
153           Only check the cfg file for errors. Do not do anything.
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155       --pid-file=s
156           Define the name and path of the pid file for mrtg running as a
157           daemon
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159       --log-only
160           Only update the logfile, do not produce graphics or html pages
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162       --debug=s
163           Enable debug options. The argument of the debug option is a comma
164           separated list of debug values:
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166            cfg  - watch the config file reading
167            dir  - directory mangeling
168            base - basic program flow
169            tarp - target parser
170            snpo - snmp polling
171            fork - forking view
172            time - some timing info
173            log  - logging of data via rateup or rrdtool
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175           Example:
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177            --debug="cfg,snpo"
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READ ON

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

184       Tobias Oetiker <tobi@oetiker.ch> and many contributors
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1882.17.7                            2018-07-13                           MRTG(1)
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