reference - MRTG 2.9.25 configuration reference
The runtime behaviour of MRTG is governed by a configuration file. Run of the mill configuration files can be generated with cfgmaker. (Check the cfgmaker manpage). But for more elaborate configurations some hand tuning is required.
This document describes all the configuration options understud by the mrtg software.
MRTG configuration file syntax follows some simple rules:
WorkDir specifies where the logfiles and the webpages should be created.
HtmlDir specifies the directory where the html (or shtml, but we'll get on to those later,) lives.
NOTE: Workdir overrides the settings for htmldir, imagedir and logdir
ImageDir specifies the directory where the images live, they should be under the html directory.
LogDir specifies the directory where the logs are stored. This need not be under htmldir directive.
An a system that can fork (UNIX for example) mrtg can fork itself into multiple instances while it is acquiring data via snmp.
For situations with high latency or a great number of devices this will speed things up considerably. It will not make things faster though if you query a single switch sitting next door.
As far as I know NT can not fork so this option is not available on NT.
How many seconds apart should the browser (Netscape) be instructed to reload the page? If this is not defined, the default is 300 seconds (5 minutes).
How often do you call mrtg? The default is 5 minutes. If you call it less often, you should specify it here. This does two things:
In this example we tell mrtg that we will be calling it every 10 minutes. If you are calling mrtg every 5 minutes, you can leave this line commented out.
Note, that unless you are using rrdtool you can not set Interval to less than 5 minutes. If you are using rrdtool you can set interval down to 1 Minute. Note though, setting the Interval for an rrdtool/mrtg setup will influence the initial creation of the database. If you change the interval later, all existing databases will remain at the resolution they were initially created with.
With this switch mrtg will generate .meta files for CERN and Apache servers which contain Expiration tags for the html and gif files. The *.meta files will be created in the same directory as the other files, so you will have to set ``MetaDir .'' and ``MetaFiles on'' in your apache.conf or .htaccess file for this to work
NOTE: If you are running Apache-1.2 or later, you can use the mod_expire to achieve the same effect ... see the file htaccess.txt
Normally we ask the SNMP device for 'sysUptime', 'sysName' properties some do not have these. If you want to avoid getting complaints from mrtg about these missing properties, specivy the nomib2 option.
An example of agents which do not implement base mib2 attributes are Computer Associates - Unicenter TNG Agents. CA relies on using the base OS SNMP agent in addition to its own agents to supplement the management of a system.
Some SNMP implementations can not deal with requests asking for multiple snmp variables in one go. Set this in your cfg file to force mrtg to only ask for one variable per request.
Apart form the per target timeout options, you can also configure the behaviour of the snmpget process on a more profound level. SnmpOptions accepts a hash of options. The following options are currently supported:
timeout => $default_timeout, retries => $default_retries, backoff => $default_backoff, default_max_repetitions => $max_repetitions, lenient_source_port_matching => 0, lenient_source_address_matching => 1
The values behind the options indicate the current default value. Note that these settings OVERRIDE the per target timeout settings.
SnmpOptions: retries => 2, only_ip_address_matching => 0
Note that AS/400 snmp seems to be broken in a way which prevents mrtg from working with it unless
SnmpOptions: lenient_source_port_matching => 1
If you want to keep the mrtg icons in some place other than the working (or imagedir) directory, use the IconDir variable for defining the url to the icons directory.
Load the MIB
Switch output format to the selected Language (Check the translate directory to see which languages are supported at the moment. In this directory you can also find instructions on how to create new translations).
Currently the following laguages are supported:
big5 brazilian bulgarian catalan chinese croatian czech danish dutch eucjp french galician gb gb2312 german greek hungarian icelandic indonesia iso2022jp italian korean lithuanian malay norwegian polish portuguese romanian russian russian1251 serbian slovak slovenian spanish swedish turkish ukrainian
Setting LogFormat to 'rrdtool' in your mrtg.cfg file enables rrdtool mode. In rrdtool mode, mrtg relies on rrdtool to do its logging. Graphs and html pages will be generated on the fly by the 14all.cgi which can be found in the contrib section together with a short readme ... This feature has been contributed by Rainer Bawidamann <email@example.com>. Please check his website for more information: http://www.wh-hms.uni-ulm.de/~widi/14all/
If you are using rrdtool mode and your rrdtool Perl module (RRDs.pm) is not installed in a location where perl can find it on its own, you can use LibAdd to supply an appropriate path.
If the rrdtool executable can not be found in the normal
The RunAsDaemon keyword enables daemon mode operation. The purpose of daemon mode is that MRTG is launched once and not at regular basis by cron as in native mode. This behavior saves computing resourses as loading and parsing of configuration files only hapens once.
Using daemon mode MRTG itself is responible for timing the measurement intervals. Therfore its important to set the Interval keyword to an apropiate value.
Note that using daemon mode MRTG should no longer be started from cron by regular basis as each started process runs forever. Instead MRTG should be started from the command prompt or by a system startup script.
If you want mrtg to run under a particular user and group (it is not recomended to run MRTG as root) then you can use the --user=user_name and --group=group_name options on the mrtg commandline.
mrtg --user=mrtg_user --group=mrtg_group mrtg.cfg
Also note that in daemon mode restart of the process is required in order to activate changes in the config file.
Under UNIX, the Daemon switch causes mrtg to fork into background after checking its config file. On Windows NT the MRTG process will detach from the console, but because the NT/2000 shell waits for its children you have to use the special start sequence when you launch the program:
start /b perl mrtg mrtg.cfg
You may have to add path information equal to what you add when you run mrtg from the commandline.
Makes MRTG run as a daemon beginning data collection every 5 minutes
Each monitoring target must be identified by a unique name. This name must be appended to each parameter belonging to the same target. The name will also be used for naming the generated webpages, logfiles and images for this target.
With the Target keyword you tell mrtg what it should monitor. The Target keyword takes arguments in a wide range of formats:
The maximum value either of the two variables monitored are allowed to reach. For monitoring router traffic this is normally specified in bytes per second this interface port can carry.
If a number higher than MaxBytes is returned, it is ignored. Also read the section on AbsMax for further info. The MaxBytes value is also used in calculating the Y range for unscaled graphs (see the section on Unscaled).
Since most links are rated in bits per second, you need to divide their maximum bandwidth (in bits) by eight (8) in order to get bytes per second. This is very important to make your unscaled graphs display realistic information. T1 = 193000, 56K = 7000, Ethernet = 1250000. The MaxBytes value will be used by mrtg to decide whether it got a valid response from the router.
If you need two different MaxBytes values for the two monitored variables, you can use MaxBytes1 and MaxBytes2 instead of MaxBytes.
Title for the HTML page which gets generated for the graph.
Title[ezwf]: Traffic Analysis for Our Nice Company
Things to add to the top of the generated HTML page. Note that you can have several lines of text as long as the first column is empty.
Note that the continuation lines will all end up on the same line in the html page. If you want linebreaks in the generated html use the '\n' sequence.
PageTop[ezwf]: <H1>Traffic Analysis for ETZ C95.1</H1> Our Campus Backbone runs over an FDDI line\n with a maximum transfer rate of 12.5 megabytes per Second.
In cases where you calculate the used bandwidth from several interfaces you normaly don't get the router uptime and router name displayed on the web page.
If these interfaces are on the same router and the uptime and name should be displayed nevertheless you have to specify its community and address again with the RouterUptime keyword.
Target[kacisco.comp.edu]: 1:firstname.lastname@example.org + 2:email@example.com RouterUptime[kacisco.comp.edu]: firstname.lastname@example.org
Same as MaxBytes, for variable 1.
Same as MaxBytes, for variable 2.
Things to add to the bottom of the generated HTML page. Note that you can have several lines of text as long as the first column is empty.
Note that the continuation lines will all end up on the same line in the html page. If you want linebreaks in the generated html use the '\n' sequence.
The material will be added just before the </BODY> tag:
PageFoot[ezwf]: Contact <A HREF="mailto:email@example.com">Peter</A> if you have questions regarding this page
Use this tag like the PageTop header, but its contents will be added between </TITLE> and </HEAD>.
AddHead[ezwf]: <link rev="made" href="mailto:firstname.lastname@example.org">
BodyTag lets you supply your very own <body ...> tag for the generated webpages.
BodyTag[ezwf]: <BODY LEFTMARGIN="1" TOPMARGIN="1" BACKGROUND="/stats/images/bg.neo2.gif">
If you are monitoring a link which can handle more traffic than the MaxBytes value. Eg, a line which uses compression or some frame relay link, you can use the AbsMax keyword to give the absolute maximum value ever to be reached. We need to know this in order to sort out unrealistic values returned by the routers. If you do not set AbsMax, rateup will ignore values higher than MaxBytes.
By default each graph is scaled vertically to make the actual data visible even when it is much lower than MaxBytes. With the Unscaled variable you can suppress this. It's argument is a string, containing one letter for each graph you don't want to be scaled: d=day w=week m=month y=year. In the example scaling for the yearly and the monthly graph are suppressed.
By default the graphs only contain the average values of the monitored variables - normally the transfer rates for incoming and outgoing traffic. The following option instructs mrtg to display the peak 5 minute values in the [w]eekly, [m]onthly and [y]early graph. In the example we define the monthly and the yearly graph to contain peak as well as average values.
By default mrtg produces 4 graphs. With this option you can suppress the generation of selected graphs. The option value syntax is analogous to the above two options. In this example we suppress the yearly graph as it is quite empty in the beginning.
By default, mrtg creates .html files. Use this option to tell mrtg to use a different extension. For example you could set the extension to php3, then you will be able to enclose PHP tags into the output (usefull for getting a router name out of a database).
By default, mrtg puts all the files that it generates for each target (the GIFs, the HTML page, the log file, etc.) in WorkDir.
If the Directory option is specified, the files are instead put into a directory under WorkDir or Log-, Image- and HtmlDir). (For example the Directory option below would cause all the files for a target ezwf to be put into directory /usr/tardis/pub/www/stats/mrtg/ezwf/ .)
The directory must already exist; mrtg will not create it.
WorkDir: /usr/tardis/pub/www/stats/mrtg Directory[ezwf]: ezwf
NOTE: the Directory option must always be 'relative' or bad things will happen.
By default mrtgs graphs are 100 by 400 pixels wide (plus some more for the labels. In the example we get almost square graphs ...
Note: XSize must be between 20 and 600; YSize must be larger than 20
XSize[ezwf]: 300 YSize[ezwf]: 300
If you want your graphs to have larger pixels, you can ``Zoom'' them.
XZoom[ezwf]: 2.0 YZoom[ezwf]: 2.0
If you want your graphs to be actually scaled use XScale and YScale. (Beware while this works, the results look ugly (to be frank) so if someone wants to fix this: patches are welcome.
XScale[ezwf]: 1.5 YScale[ezwf]: 1.5
If you want to show more than 4 lines per graph, use YTics. If you want to scale the value used for the YLegend of these tics, use YTicsFactor. The default value for YTics is 4 and the default value for YTicsFactor is 1.0 .
Suppose you get values ranging from 0 to 700. You want to plot 7 lines and want to show 0, 1, 2, 3, 4, 5, 6, 7 instead of 0, 100, 200, 300, 400, 500, 600, 700. You should write then:
YTics[ezwf]: 7 YTicsFactor[ezwf]: 0.01
If you want to multiply all numbers shown below the graph with a constant factor, use this directive to define it ..
Change the default step from 5 * 60 seconds to something else (I have not tested this well ...)
The Options Keyword allows you to set some boolean switches:
Options[ezwf]: growright, bits
Use this option to change the multiplier value for building prefixes. Defaultvalue is 1000. This tag is for the special case that 1kB = 1024B, 1MB = 1024kB and so far.
Change the default multiplier prefixes (,k,M,G,T,P). In the tag ShortLegend define only the basic units. Format: Comma seperated list of prefixed. Two consecutive commas or a comma at start or end of the line gives no prefix on this item. Note: If you do not want prefixes, then leave this line blank.
Example: velocity in nm/s (nanometers per second) displayed in nm/h.
ShortLegend[ezwf]: m/h kMG[ezwf]: n,u,m,,k,M,G,T,P options[ezwf]: perhour
The Colours tag allows you to override the default colour scheme. Note: All 4 of the required colours must be specified here. The colour name ('Colourx' below) is the legend name displayed, while the RGB value is the real colour used for the display, both on the graph and in the html doc.
Format is: Col1#RRGGBB,Col2#RRGGBB,Col3#RRGGBB,Col4#RRGGBB
Important: If you use the dorelpercent options tag a fifth colour name colour value pair is required: Col1#RRGGBB,Col2#RRGGBB,Col3#RRGGBB,Col4#RRGGBB,Col5#RRGGBB
Colours[ezwf]: GREEN#00eb0c,BLUE#1000ff,DARK GREEN#006600,VIOLET#ff00ff
With the Background tag you can configure the background colour of the generated HTML page
The following keywords allow you to override the text displayed for the various legends of the graph and in the HTML document
YLegend[ezwf]: Bits per Second ShortLegend[ezwf]: b/s Legend1[ezwf]: Incoming Traffic in Bits per Second Legend2[ezwf]: Outgoing Traffic in Bits per Second Legend3[ezwf]: Maximal 5 Minute Incoming Traffic Legend4[ezwf]: Maximal 5 Minute Outgoing Traffic LegendI[ezwf]: In: LegendO[ezwf]: Out:
Note, if LegendI or LegendO are set to an empty string with
The corresponding line below the graph will not be printed at all.
If you live in an international world, you might want to generate the graphs in different timezones. This is set in the TZ variable. Under certain operating systems like Solaris, this will provoke the localtime call to give the time in the selected timezone ...
The Timezone is the standard Solaris timezone, ie Japan, Hongkong, GMT, GMT+1 etc etc.
By default, mrtg (actually rateup) uses the
This affects the creation of new rrd files. By default rrds are created to hold about 1 days worth of high resolution data. (plus 1 week of 30 minute data, 2 month of 2 hour data and 2 years of 1 day data). Whith this Keyword you can change the number of base interval entries configured for new rrds as they get created. Note that you must take the interval time into account.
Through its threshold checking functionality mrtg is able to detect threshold problems for the various targets and can call external scripts to handle those problems (send email or a page to an administrator).
Threshold checking is configured through the following parameters:
By defining ThreshDir to point to a writable directory, MRTG will only alert you when a threshold boundery has been crossed.
This is the minimum acceptable value for the Input (first) parameter. If the parameter falls below this value, the program specified in ThreshProgI will be run. If the value ends in '%' then the threshold is defined relative to MaxBytes.
This is the maximum acceptable value for the Input (first) parameter. If the parameter falls above this value, the program specified in ThreshProgI will be run. If the value ends in '%' then the threshold is defined relative to MaxBytes.
Its value will be assigned to the environment variable THRESH_DESC before any of the programs mentioned below are called. The programms can use the value of this variable to produce more userfriendly output.
This defines a program to be run if ThreshMinI or ThreshMaxI is broken. MRTG passes 3 arguments: the $router variable, the threshold value broken, and the current parameter value.
This defines a program to be run if the parameter is currently OK (based on ThreshMinI and ThreshMaxI), but wasn't OK on the previous running -- based on the files found in ThreshDir. MRTG passes 3 arguments: the $router variable the un-broken threshold value, and the current parameter value.
They work the same as their *I counterparts, except on the Output (second) parameter.
Note, that you can use the SetEnv parameter explained above to pass additional information to the threshold programs.
When calling threshol scripts from within your cfg file you might want to pass some data on to the script. This can be done with the SetEnv configuration option ... it takes a series of environment variable assignments. Note that the quotes are mandatory. Note that this does not work for external scripts because of the way mrtg evaluates them it is not possible to set environment variables per target.
SetEnv[myrouter]: EMAIL="email@example.com" HOST="www.some_server.net" URL="http://www.some_server.net/path/mrtg.html"
To save yourself some typing you can define a target called '^'. The text of every Keyword you define for this target will be PREPENDED to the corresponding Keyword of all the targets defined below this line. The same goes for a Target called '$' but its text will be APPENDED.
Note that a space is inserted between the prepended text and the Keyword value, as well as between the Keyword value and the appended text. This works well for text-valued Keywords, but is not very useful for other Keywords. See the ``default'' target description below.
The example will make mrtg use a common header and a common contact person in all the pages generated from targets defined later in this file.
PageTop[^]: <H1>NoWhere Unis Traffic Stats</H1><HR> PageTop[$]: Contact Peter Norton if you have any questions<HR>
To remove the prepend/append value, specify an empty value, e.g.:
NOTE: With PREPEND and APPEND there is normally a space inserted between the local value and the PRE- or APPEND value. Sometimes this is not desirable. You can use the NoSpaceChar config option to define a character which can be mentioned at the end of a $ or ^ definition in order to supress the space.
NoSpaceChar: ~ Target[^]: 184.108.40.206.4.1.4220.127.116.11.20.0&18.104.22.168.4.1.422.214.171.124.21.0:get@~ Target[a]: a.tolna.net Target[b]: b.tolna.net Target[c]: c.tolna.net Target[d]: d.tolna.net
The target name '_' specifies a default value for that Keyword. In the absence of explicit Keyword value, the prepended and the appended keyword value, the default value will be used.
YSize[_]: 150 Options[_]: growright,bits,nopercent WithPeak[_]: ymw Suppress[_]: y MaxBytes[_]: 1250000
To remove the default value and return to the 'factory default', specify an empty value, e.g.:
There can be several instances of setting the default/prepend/append values in the configuration file. The later setting replaces the previous one for the rest of the configuration file. The default/prepend/append values used for a given keyword/target pair are the ones that were in effect at the point in the configuration file where the target was mentioned for the first time.
MaxBytes[_]: 1250000 Target[myrouter.somplace.edu.2]: 2:firstname.lastname@example.org MaxBytes[_]: 8000 Title[myrouter.somplace.edu.2]: Traffic Analysis for myrouter.somplace.edu IF 2
The default MaxBytes for the target myrouter.somplace.edu.2 in the above example will be 1250000, which was in effect where the target name myrouter.somplace.edu.2 first appeared in the config file.
WorkDir: /usr/tardis/pub/www/stats/mrtg Target[r1]: 2:email@example.com MaxBytes[r1]: 8000 Title[r1]: Traffic Analysis ISDN PageTop[r1]: <H1>Stats for our ISDN Line</H1>
WorkDir: /usr/tardis/pub/www/stats/mrtg Title[^]: Traffic Analysis for PageTop[^]: <H1>Stats for PageTop[$]: Contact The Chief if you notice anybody<HR> MaxBytes[_]: 8000 Options[_]: growright
Title[isdn]: our ISDN Line PageTop[isdn]: our ISDN Line</H1> Target[isdn]: 2:firstname.lastname@example.org
Title[backb]: our Campus Backbone PageTop[backb]: our Campus Backbone</H1> Target[backb]: 1:email@example.com MaxBytes[backb]: 1250000
# the following line removes the default prepend value # defined above
Title[isdn2]: Traffic for the Backup ISDN Line PageTop[isdn2]: our ISDN Line</H1> Target[isdn2]: 3:firstname.lastname@example.org
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