1MRTG(1)                              mrtg                              MRTG(1)
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NAME

6       mrtg - What is MRTG ?
7

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.
12       Check http://www.stat.ee.ethz.ch/mrtg/ to see what it does.
13
14       Go to
15        http://oss.oetiker.ch/mrtg for all the details about mrtg.
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HIGHLIGHTS

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

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

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

112       Mrtg is also the name of the script you have to run to poll data and
113       generate the graphs. Most configuration is set through the
114       configuration file; some command-line options exist all the same.
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116       --user username  and --group groupname
117           Run as the given user and/or group. (Unix Only)
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119       --lock-file filename
120           Use an alternate lock-file (the default is to use the
121           configuration-file appended with "_l").
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123       --confcache-file filename
124           Use an alternate confcache-file (the default is to use the
125           configuration-file appended with ".ok")
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127       --logging filename|eventlog
128           If this is set to writable filename, all output from mrtg
129           (warnings, debug messages, errors) will go to filename. If you are
130           running on Win32 you can specify eventlog instead of a filename
131           which will send all error to the windows event log.
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133           NOTE:Note, there is no Message DLL for mrtg. This has the side
134           effect that the windows event logger will display a nice message
135           with every entry in the event log, complaing about the fact that
136           mrtg has no message dll. If any of the Windows folks want to
137           contribute one, they are welcome.
138
139       --daemon
140           Put MRTG into the background, running as a daemon. This works the
141           same way as the config file option, but the switch is required for
142           proper FHS operation (because /var/run is writable only by root)
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144       --fhs
145           Configure all mrtg paths to conform to the FHS specification;
146           http://www.pathname.com/fhs/
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148       --check
149           Only check the cfg file for errors. Do not do anything.
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151       --pid-file=s
152           Define the name and path of the pid file for mrtg running as a
153           daemon
154
155       --log-only
156           Only update the logfile, do not produce graphics or html pages
157
158       --debug=s
159           Enable debug options. The argument of the debug option is a comma
160           separated list of debug values:
161
162            cfg  - watch the config file reading
163            dir  - directory mangeling
164            base - basic program flow
165            tarp - target parser
166            snpo - snmp polling
167            fork - forking view
168            time - some timing info
169            log  - logging of data via rateup or rrdtool
170
171           Example:
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173            --debug="cfg,snpo"
174

READ ON

176       Learn more about MRTG by going to the mrtg home page on:
177       http://oss.oetiker.ch/mrtg
178

AUTHOR

180       Tobias Oetiker <tobi@oetiker.ch> and many contributors
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1842.16.4                            2010-05-17                           MRTG(1)
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