manual.txt

主要用于监控网络流量并动态产生可视化结果

   The Multi Router Traffic Grapher
   
MRTG 2.8.12

   Programming by [1]Tobias Oetiker [2]<[e-mail]>
   [3]Dave Rand [4]<[e-mail]>
   and a number of other people from the Global-Village
   Documentation by [5]Tobias Oetiker [6]<[e-mail]>
   Domain Reflectors: [7]www.mrtg.org (by Timothy Kennedy of [8]Erol's
   Internet Service), [9]mrtg.eu.org (by Michel Renfer of [10]LAN
   Services AG), [11]mrtg.net.ru (by Andrey G. Sergeev
   <[12][e-mail]>).
   Active WWW Mirrors: [13]Swiss Original, [14]JP, [15]USA, [16]CZ,
   [17]BR, [18]BR, [19]UK, [20]TH, [21]UK.
   Not so Active WWW Mirrors: [22]AU, [23]USA, [24]RO, [25]PL, [26]JP,
   [27]JP.
   Active FTP Mirrors: [28]US, [29]Poland, [30]CZ, [31]SE, [32]DE,
   [33]IT, [34]US, [35]TH, [36]RU, [37]UK, [38]BR, [39]JP, [40]JP.
   Less Active FTP Mirrors: [41]USA III, [42]RO, [43]NO.
   Translations: [44]Japanese.
   
   Contents 
     * [45]What is the Multi Router Traffic Grapher
     * [46]Highlights of MRTG
     * [47]The History
     * [48]Release Notes
     * [49]Getting and Installing MRTG
     * [50]Configuration Tips
     * [51]Frequently Asked Questions
     * [52]MRTG on the Usenet
     * [53]The MRTG Mailing List
     * [54]Windows NT Notes
       
   What is the Multi Router Traffic Grapher 
   
   The Multi Router Traffic Grapher (MRTG) is a tool to monitor the
   traffic load on network-links. MRTG generates HTML pages containing
   GIF images which provide a LIVE visual representation of this traffic.
   Check [55]http://www.ee.ethz.ch/stats/mrtg/ for an example. MRTG is
   based on Perl and C and works under UNIX and Windows NT. MRTG is being
   successfully used on many sites around the net. Check the
   [56]MRTG-Site-Map.
   MRTG is available under the [57]GNU General Public License
   If you like MRTG and want to show me your appreciation, you are
   welcome to have a look at my [58]music CD wishlist . This address
   redirects you to the shop where I am currently keeping my wishlist.
   Please put your eMail address into the the Message area, so that I can
   thank you for your present. I do keep a list of People who sent me
   CDs. You can look at it [59]here. Please do not make them send the CDs
   via an express carrier because I pay about 14$ duty and handling
   charge for each one.
   
   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 four 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 50 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.
   
   Highlights of MRTG 
    1. Works on most UNIX platforms and Windows NT
    2. Uses Perl for easy customization
    3. Has a highly portable SNMP implementation written entirely in Perl
       thanks to Simon Leinen. There is no need to install any external
       SNMP package.
    4. MRTG's logfiles do NOT grow. Thanks to the use of a unique data
       consolidation algorithm.
    5. MRTG comes with a semi-automatic configuration tool.
    6. MRTG's query engine checks for port reconfigurations on the router
       and warns the user when they occur.
    7. Time critical routines are written in C thanks to the initiative
       of Dave Rand my Co-Author
    8. Graphics are generated directly in GIF format, using the GD
       library by Thomas Boutell.
    9. This package produces PNG or GIF format, depending on the version
       of GDLIB used to build MRTG. GDLIB prior to 1.3 produce LZW
       compressed GIFS, version 1.3-1.5 uses run-length compression and
       Version 1.6 and later use PNG format. Thus, users in the US should
       make sure they link with the right Version of GDLIB.
   10. The look of the webpages produced by MRTG is highly configurable.
   11. MRTG is available under the GNU General Public License.
       
   History of MRTG 
   
   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, showing 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 is the
   result of a wonderful collaboration of many people. I would like to
   take this opportunity to thank them all. (See the files CHANGES for a
   long list of friendly people who helped to make MRTG what it is today)
   
   Release Notes 
   
   Check the latest release notes by going to the mrtg [60]CHANGES file.
   
   Getting and Installing MRTG on a UNIX system 
    1. Get the latest Version of MRTG from:
       [61]http://ee-staff.ethz.ch/~oetiker/webtools/mrtg/pub/
    2. Get and compile the GD library by Thomas Boutell:
       [62]www.boutell.com. Unless you know what you are doing, make sure
       you build libgd, zlib and libpng as static libraries. There are
       detailed instructions in the README file which comes int the MRTG
       archive.
    3. Make sure you have Perl Version 5.004_4 or later on your system:
       [63]http://www.perl.com/perl/info/software.html
    4. type ./configure this will prepare MRTG for your system. if
       something is missing, configure will tell you what todo about it.
       (Again, see the README file for some more on this.)
    5. run make to build the rateup executable and edit the perl path in
       mrtg and its companion tools.
    6. Decide where MRTG should store the webpages it creates. Copy the
       images/mrtg*.png files into this directory. They will be
       referenced in the generated webpages.
    7. The run directory contains all the files, MRTG needs to operate.
       This directory can be anywhere because MRTG will find its location
       upon startup.
    8. Now create your personal mrtg.cfg file. You can find the
       documentation about this in the file [64]config.html See the
       Configuration hints section for some further help. The difficult
       part in creating the configuration file is getting your
       router-port assignment correct. To help you with this, the
       cfgmaker tool will generate all the router specific parts of your
       configuration file.
       
     cfgmaker <community>@<router-host-name or IP>
       If you don't know the community of your router, try public as
       community name. When using cfgmaker, make sure to add the WorkDir:
       parameter to the resulting config file.
    9. Try to start MRTG. Type ./mrtg mrtg.cfg on the command line, while
       you are in your MRTG run directory. MRTG will now parse your
       configuration file, and complain if you have introduced any
       unknown keywords or structures. If MRTG is happy with the cfg
       file, it starts gathering traffic data from the routers you have
       specified. With this information it will then start the rateup
       tool which will create a logfile and a traffic graph GIF for each
       Target. When you start MRTG for the very first time, rateup will
       complain that it can not find any logfiles and the graphs
       generated will look rather empty. Just ignore the complaints. If
       you remove the empty graphs, and run MRTG again, rateup will
       create new graphs which look better.
   10. Integrate MRTG into your crontab. Just add the following line to
       your crontab file to have MRTG run every 5 minutes (The line is
       broken for readability only. Replace the backslash in the first
       line with the second line):
       0,5,10,15,20,25,30,35,40,45,50,55 * * * * \
       <mrtg-bin>/mrtg <path to mrtg-cfg>/mrtg.cfg
       
   Configuration Tips 
     * If you are monitoring a number of links, you might want to create
       an overview page. For our own site I have created the indexmaker
       script, which you can use to create a html page containing hrefs
       that point to your individual traffic statistics pages. Note, that
       you need to edit this script for your purposes. The script you
       got, includes our Universities Logo
       (http://www.ee.ethz.ch/eth.199x32.gif) into the page.
       indexmaker <mrtg.cfg> <regexp for router-names>
     * If you are monitoring many targets, use the special target names
       '^' and '$' to prepend or append text to any of the Keywords in
       the sections below. Note that the definition of the '^' and '$'
       targets are position dependant. They always influence the lines
       below in the cfg file. The special target '_' for specifying
       defaults may come handy as well.
     * Since MRTG updates it's graphs every 5 minutes, you may experience
       problems with proxy caches and local Netscape browser caches.
       Sometimes these caches will return the old cached graphics instead
       of the real and updated versions from the webserver.
       If you are running the apache webserver, you can use the
       WriteExpire Keyword in the mrtg.cfg file. With this, mrtg will
       create *.meta files for each gif and html page. These files will
       contain 'Expire' headers which the Apache webserver can ship out
       together with the gif and html pages (Use to MetaDir keyword in
       the apache config file to enable this). With the information from
       the expire headers, Netscape and all the proxy caches will know
       when they have to fetch a new version of the file from your
       website and when they can use their cached version.
     * Although MRTG's primary use is traffic monitoring, you can observe
       any SNMP variable you want. People are using it to monitor
       ModemBanks, ServerLoad, ErrorRates on Interfaces and many other
       things. If you are using MRTG for something other than traffic
       monitoring, please send me a short blurb to include here. Best
       would be with a sample URL and some hints about how you have
       configured MRTG ... Check the [65]MRTG-Site-Map for other peoples
       work related to this.
     * Some monitored devices such as routers may have cards which can be
       moved around inside. When this happens data that once was read
       from one interface index now appears on a new index. This can
       confuse data collection. Often MRTG will notice the change and
       report the following:
       -------------------------------------------------------------------
       Warning: There is something wrong with Target 1.2.3.4

       * Its ifDescr used to be etc4p4
       * Now it is etc3p4

       I will not update this graph for the moment. Maybe your Router has
       changed the port to interface mapping. This can happen when new
       Interfaces are added to the router or when it is rebooted.

       You should alter your 1.2.3.4.cfg file to fix the mapping and then
       remove the offending lines from your 1.2.3.4.ok file. Mrtg will
       then assume that everything is OK and create new entries representing
       the new matching.
       --------------------------------------------------------------------

       You can help prevent this problem by using either IP addresses or
       Physcial Address instead of the default Interface Indices. The
       program cfgmaker_phys can convert your *.cfg files to use Physical
       Addresses. See config.txt for more information.
       
   Frequently Asked Question with Answers 
   
   Q: Why is there no "@#$%" (my native language) version of MRTG.
   A: Nobody has contributed a "@#$%.pmd" file. Go into the "translate"
   directory and create your own translation file. When you are happy
   with it send it to me for inclusion with the next mrtg release.