REFERENCE(1)                         mrtg                         REFERENCE(1)


       reference - MRTG 2.10.5 configuration reference


       The runtime behaviour of MRTG is governed by a configuration file.
       Run-of- ther-mill configuration files can be generated with cfgmaker.
       (Check cfgmaker). But for more elaborate configurations some hand-tun-
       ing is required.

       This document describes all the configuration options understood by the
       mrtg software.


       MRTG configuration file syntax follows some simple rules:

       ·   Keywords must start at the beginning of a line.

       ·   Lines which follow a keyword line which start with a blank are
           appended to the keyword line

       ·   Empty Lines are ignored

       ·   Lines starting with a # sign are comments.

       ·   You can add other files into the configuration file using

           Include: file



           If included files are specified with relative paths, both the cur-
           rent working directory and the directory containing the main config
           file will be searched for the files.



       WorkDir specifies where the logfiles and the webpages should be cre-


        WorkDir: /usr/tardis/pub/www/stats/mrtg



       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.


        Htmldir: /www/mrtg/


       ImageDir specifies the directory where the images live. They should be
       under the html directory.


        Imagedir: /www/mrtg/images


       LogDir specifies the directory where the logs are stored.  This need
       not be under htmldir directive.


        Logdir: /www/mrtg/logs

       Forks (UNIX only)

       With system that supports 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.


        Forks: 4


       When set to yes, IPv6 support is enabled if the required libraries are
       present (see the mrtg-ipv6 manpage). When IPv6 is enabled, mrtg can
       talk to routers using SNMP over IPv6 and targets may be specified by
       their numeric IPv6 addresses as well as by hostname or IPv4 address.

       If IPv6 is enabled and the target is a hostname, mrtg will try to
       resolve the hostname to an IPv6 address and, if this fails, to an IPv4
       address.  Note that mrtg will only use IPv4 if you specify an IPv4
       address or a hostname with no corresponding IPv6 address; it will not
       fall back to IPv4 if it simply fails to communicate with the target
       using IPv6. This is by design.

       Note that many routers do not currently support SNMP over IPv6. Use the
       IPv4Only per target option for these routers.

       IPv6 is disabled by default.


        EnableIPv6: Yes


       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


        Refresh: 600


       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:

       ·   The generated HTML page contains the right information about the
           calling interval ...

       ·   A META header in the generated HTML page will instruct caches about
           the time-to-live of this page .....

       In this example, we tell mrtg that we will be calling it every 10 min-
       utes. If you are calling mrtg every 5 minutes, you can leave this line
       commented out.


        Interval: 10

       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


        WriteExpires: Yes


       Normally we ask the SNMP device for ’sysUptime’ and ’sysName’ proper-
       ties.  Some do not have these. If you want to avoid getting complaints
       from mrtg about these missing properties, specify 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 man-
       agement of a system.


        NoMib2: Yes


       Some SNMP implementations can not deal with requests asking for multi-
       ple snmp variables in one go. Set this in your cfg file to force mrtg
       to only ask for one variable per request.


        SingleRequest: Yes


       Apart from 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 sup-

        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

       is set.


       If you want to keep the mrtg icons in someplace other than the working
       (or imagedir) directory, use the IconDir variable for defining the url
       of the icons directory.


        IconDir: /mrtgicons/


       Load the MIB file(s) specified and make its OIDs available as symbolic
       names. For better efficiancy, a cache of MIBs is maintained in the


        LoadMIBs: /dept/net/mibs/netapp.mib,/usr/local/lib/ft100m.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 transla-

       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 span-
       ish swedish turkish ukrainian


        Language: danish


       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 <baw->. Please check his website for more infor-


        LogFormat: rrdtool


       If you are using rrdtool mode and your rrdtool Perl module ( is
       not installed in a location where perl can find it on its own, you can
       use LibAdd to supply an appropriate path.


        LibAdd: /usr/local/rrdtool/lib/perl/


       If the rrdtool executable can not be found in the normal "PATH", you
       can use this keyword to add a suitable directory to your path.


        PathAdd: /usr/local/rrdtool/bin/


       The RunAsDaemon keyword enables daemon mode operation. The purpose of
       daemon mode is that MRTG is launched once and not repeatedly (as it is
       with cron).  This behavior saves computing resourses as loading and
       parsing of configuration files happens only 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 when using daemon mode MRTG should no longer be started from
       cron as each new 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 restarting 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 this special start sequence when you launch the pro-

        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.



       This makes MRTG run as a daemon beginning data collection every 5 min-


       Some devices may produce non-numeric values that would nevertheless be
       useful to graph with MRTG if those values could be converted to num-
       bers.  The ConversionCode keyword specifies the path to a file contain-
       ing Perl code to perform such conversions. The code in this file must
       consist of one or more Perl subroutines. Each subroutine must accept a
       single string argument and return a single numeric value. When RRDtool
       is in use, a decimal value may be returned. When the name of one of
       these subroutines is specified in a target definition (see below), MRTG
       calls it twice for that target, once to convert the the input value
       being monitored and a second time to convert the output value. The sub-
       routine must return an undefined value if the conversion fails. In case
       of failure, a warning may be posted to the MRTG log file using Perl’s
       warn function. MRTG imports the subroutines into a separate name space
       (package MRTGConversion), so the user need not worry about pollution of
       MRTG’s global name space. MRTG automatically prepends this package dec-
       laration to the user-supplied code.

       Example: Suppose a particular OID returns a character string whose
       length is proportional to the value to be monitored. To convert this
       string to a number that can be graphed by MRTG, create a file arbitrar-
       ily named "" containing the following code:

        # Return the length of the string argument
        sub Length2Int {
          my $value = shift;
          return length( $value );

       Then include the following global keyword in the MRTG configuration
       file (assuming that the conversion code file is saved in the mrtg/bin
       directory along with mrtg itself):


       This will cause MRTG to include the definition of the subroutine
       Length2Int in its execution environment. Length2Int can then be invoked
       on any target by appending "│Length2Int" to the target definition as


       See "Extended Host Name Syntax" below for complete target definition
       syntax information.


       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 Tar-
       get keyword takes arguments in a wide range of formats:

           The most basic format is "port:community@router" This will generate
           a traffic graph for the interface ’port’ of the host ’router’ (dns
           name or IP address) and it will use the community ’community’ (snmp
           password) for the snmp query.



           If your community contains a "@" or a " " these characters must be
           escaped with a "\".

            Target[bla]: 2:stu\ pi\@d@router

           If you have a fast router you might want to try to poll the ifHC*
           counters.  This feature gets activated by switching to SNMPv2c.
           Unfortunately not all devices support SNMPv2c yet. If it works,
           this will prevent your counters from wraping within the 5 minute
           polling interval, since we now use 64 bit instead of the normal 32


            Target[ezwf]: 2:public@router1:::::2

           Sometimes you are sitting on the wrong side of the link, and you
           would like to have mrtg report Incoming traffic as Outgoing and
           vice versa. This can be achieved by adding the ’-’ sign in front of
           the "Target" description. It flips the incoming and outgoing traf-
           fic rates.



       Explicit OIDs
           You can also explicitly define which OID to query by using the fol-
           lowing syntax ’OID_1&OID_2:community@router’ The following example
           will retrieve error counts for input and output on interface 1.
           MRTG needs to graph two variables, so you need to specify two OID’s
           such as temperature and humidity or error input and error output.



       MIB Variables
           MRTG knows a number of symbolic SNMP variable names.  See the file
           mibhelp.txt for a list of known names.  One example are the ifIn-
           Errors and ifOutErrors.  This means you can specify the above as:


            Target[ezwf]: ifInErrors.1&ifOutErrors.1:public@myrouter

       Interface by IP
           Sometimes SNMP interface index can change, like when new interfaces
           are added or removed. This can cause all Target entries in your
           config file to become offset, causing MRTG to graphs wrong
           instances etc.  MRTG supports IP address instead of ifindex in tar-
           get definition. Then MRTG will query snmp device and try to map IP
           address to the current ifindex.  You can use IP addresses in every
           type of target definition by adding IP address of the numbered
           interface after OID and separation char ’/’.

           Make sure that the given IP address is used on your same target
           router, especially when graphing two different OIDs and/or
           interface split by ’&’ delimiter.

           You can tell cfgmaker to generate such references with the option


            Target[ezwf]: /
            Target[ezci]: -/
            Target[ezwf]: ifInErrors/

       Interface by Description
           If you can not use IP addresses you might want to use the interface
           names. This works similar to the IP address aproach except that the
           prefix to use is a \ instead of a /

           You can tell cfgmaker to generate such references with the option


            Target[ezwf]: \
            Target[ezci]: -\
            Target[ezwf]: ifInErrors\My-Interface2&ifOutErrors\My-Interface3:public@myrouter

           If your description contains a "&", a ":", a "@" or a " " you can
           include them but you must escape with a backlash:

            Target[ezwf]: \fun\:\ ney\&ddd:public@hello.router

       Interface by Name
           This is the only sensible way to reference the interfaces of your

           You can tell cfgmaker to generate such references with the option


            Target[ezwf]: #2/
            Target[ezci]: -#2/
            Target[ezwf]: ifInErrors#3/7&ifOutErrors#3/7:public@myrouter

           If your description contains a "&", a ":", a "@" or a " " you can
           include them but you must escape with a backlash:

            Target[ezwf]: #\:\ fun:public@hello.router

           <Note that the # sign will be interpreted as a comment character if
           it is the first non white-space character on the line.>

       Interface by Ethernet Address
           When the SNMP interface index changes, you can key that interface
           by its ’Physical Address’, sometimes called a ’hard address’, which
           is the SNMP variable ’ifPhysAddress’.  Internally, MRTG matches the
           Physical Address from the *.cfg file to its current index, and then
           uses that index for the rest of the session.

           You can use the Physical Address in every type of target definition
           by adding the Physical Address after the OID and the separation
           char ’!’ (analogous to the IP address option).  The Physical
           address is specified as ’-’ delimited octets, such as
           "0a-0-f1-5-23-18" (omit the double quotes). Note that some routers
           use the same Hardware Ethernet Address for all of their Interfaces
           which prevents unique interface identification. Mrtg will notice
           such problems and alert you.

           You can tell cfgmaker to generate configuration files with hardware
           ethernet address references by using the option --ifref=eth.


            Target[ezwf]: !
            Target[ezci]: -!
            Target[ezwf]: ifInErrors!0a-00-10-23-44-51&ifOutErrors!0a-00-10-23-44-51:public@myrouter

       Interface by Type
           It seems that there are devices that try to defy all monitoring
           efforts: the interesting interfaces have neither ifName nor a con-
           stant ifDescr not to mention a persistant ifIndex. The only way to
           get a constant mapping is by looking at the interface type, because
           the interface you are interested in is unique in the device you are
           looking at ...

           You can tell cfgmaker to generate such references with the option


            Target[ezwf]: ifInErrors%13&ifOutErrors%14:public@myrouter

       Extended Host Name Syntax
           In all places where ‘‘community@router’’ is accepted, you can add
           additional parameters for the SNMP communication using colon-sepa-
           rated suffixes. You can also append a pipe symbol ( │ ) and the
           name of a numeric conversion subroutine as described under the
           global keyword "ConversionCode" above. The full syntax is as fol-


           where the meaning of each parameter is as follows:

               the UDP port under which to contact the SNMP agent (default:

               initial timeout for SNMP queries, in seconds (default: 2.0)

               number of times a timed-out request will be retried (default:

               factor by which the timeout is multiplied on every retry
               (default: 1.0).

               for SNMP version. If you have a fast router you might want to
               put a ’2’ here. This will make mrtg try to poll the 64 bit
               counters and thus prevent excessive counter wrapping. Not all
               routers support this though.



               the name of the subroutine that MRTG will call to convert the
               input and output values to integers. See the complete example
               under the global keyword "ConversionCode" above.



               This would retrieve values from the OID for
               input and .2 for output on mydevice using UDP port 161 and SNMP
               version 2, and would execute the user-defined numeric conver-
               sion subroutine Length2Int to convert those values to integers.

           A value that equals the default value can be omitted.  Trailing
           colons can be omitted, too. The pipe symbol followed by the name
           parameter, if present, must come at the end. There must be no
           spaces around the colons or pipe symbol.



           This would refer to the input/output octet counters for the inter-
           face with ifIndex 1 on, as known by the SNMP
           agent listening on UDP port 9161.  The standard initial timeout
           (2.0 seconds) is used, but the number of retries is set to four.
           The backoff value is the default.

       Numeric IPv6 addresses
           If IPv6 is enabled you may also specify a target using its IPv6
           address. To avoid ambiguity with the port number, numeric IPv6
           addresses must be placed in square brackets.


            Target[IPv6test]: 2:public@[2001:760:4::]:6161::4

       External Monitoring Scripts
           If you want to monitor something which does not provide data via
           snmp you can use some external program to do the data gathering.

           The external command must return 4 lines of output:

           Line 1
               current state of the first variable, normally ’incoming bytes

           Line 2
               current state of the second variable, normally ’outgoing bytes

           Line 3
               string (in any human readable format), telling the uptime of
               the target.

           Line 4
               string, telling the name of the target.

           Depending on the type of data your script returns you might want to
           use the ’gauge’ or ’absolute’ arguments for the Options keyword.


            Target[ezwf]: ‘/usr/local/bin/df2mrtg /dev/dsk/c0t2d0s0‘

           Note the use of the backticks (‘), not apostrophes (’) around the

           If you want to use a backtick in the command name this can be done
           but you must escape it with a backslash ...

           If your script does not have any data to return but does not want
           mrtg to complain about invalid data, it can return ’UNKNOWN’
           instead of a number.  Note though that only rrdtool is realy
           equipped to handle unknown data well.

       Multi Target Syntax
           You can also combine several target definitions in a mathematical
           expression.  Any syntactically correct expression that the Perl
           interpreter can evaluate to will work. An expression could be used,
           for example, to aggregate both B channels in an ISDN connection or
           to calculate the percentage hard disk utilization of a server from
           the absolute used space and total capacity.


            Target[ezwf]: 2:public@wellfleetA + 1:public@wellfleetA

            Target[ezwf]: /
       * 100

           Note that whitespace must surround each target definition in the
           expression.  Target definitions themselves must not contain whites-
           pace, except in interface descriptions and interface names, where
           each whitespace character is escaped by a backslash.

           MRTG automatically rounds the result of the expression to an inte-
           ger unless RRDTool logging is in use and the gauge option is in
           effect for the target.  Internally MRTG uses Perl’s Math::BigFloat
           package to calculate the result of the expression with 40 digits of
           precision. Even in extreme cases, where, for example, you take the
           difference of two 64-bit integers, the result of the expression
           should be accurate.

       SNMP Request Optimization
           MRTG is designed to economize on its SNMP requests. Where a target
           definition appears more than once in the configuration file, MRTG
           requests the data from the device only once per round of data col-
           lection and uses the collected data for each instance of a particu-
           lar target. Recognition of two target definitions as being identi-
           cal is based on a simple string match rather than any kind of
           deeper semantic analysis.


            Target[Targ1]: 1:public@CiscoA
            Target[Targ2]: 2:public@CiscoA
            Target[Targ3]: 1:public@CiscoA + 2:public@CiscoA
            Target[Targ4]: 1:public@CISCOA

           This results in a total of three SNMP requests. Data for 1:pub-
           lic@CiscoA and 2:public@CiscoA are requested only once each, and
           used for Targ1, Targ2, and Targ3. Targ4 causes another SNMP request
           for 1:public@CISCOA, which is not recognized as being identical to


       The maximum value either of the two variables monitored are allowed to
       reach. For monitoring router traffic this is normally the 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

       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 sec-
       ond.  This is very important to make your unscaled graphs display real-
       istic 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 vari-
       ables, you can use MaxBytes1 and MaxBytes2 instead of MaxBytes.


        MaxBytes[ezwf]: 1250000


       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


       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 you have to specify its community and address again
       with the RouterUptime keyword.


        Target[]: 1:public@ + 2:public@
        RouterUptime[]: public@


       If the default name of the router is incorrect/uninformative, you can
       use RouterName to specify a different OID on either the same or a dif-
       ferent host.

       A practical example: sysName on BayTech DS72 units always display
       "ds72", no matter what you set the Unit ID to be.  Instead, the Unit ID
       is stored at, so we can have MRTG display this
       instead of sysName.



       A different OID on a different host can also be specified:



       Same as MaxBytes, for variable 1.


       Same as MaxBytes, for variable 2.


       Many IPv6 routers do not currently support SNMP over IPv6 and must be
       monitored using IPv4. The IPv4Only option forces mrtg to use IPv4 when
       communicating with the target, even if IPv6 is enabled. This is useful
       if the target is a hostname with both IPv4 and IPv6 addresses; without
       the IPv4Only keyword, monitoring such a router will not work if IPv6 is

       If set to no (the default), mrtg will use IPv6 unless the target has no
       IPv6 addresses, in which case it will use IPv4. If set to yes, mrtg
       will only use IPv4.

       Note that if this option is set to yes and the target does not have an
       IPv4 address, communication with the target will fail.

       This option has no effect if IPv6 is not enabled.


        Target[v4onlyrouter_1]: 1:public@v4onlyrouter
        IPv4Only[v4onlyrouter_1]: Yes


       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:peter@x.yz">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="">


       BodyTag lets you supply your very own <body ...> tag for the generated


        BodyTag[ezwf]: <BODY LEFTMARGIN="1" TOPMARGIN="1"


       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 unreal-
       istic values returned by the routers. If you do not set AbsMax, rateup
       will ignore values higher than MaxBytes.


        AbsMax[ezwf]: 2500000


       By default each graph is scaled vertically to make the actual data vis-
       ible even when it is much lower than MaxBytes.  With the Unscaled vari-
       able 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.  There is also a special case to unset the variable completely:
       n=none. This could be useful in the event you need to override a global
       configuration. In the example scaling for the yearly and the monthly
       graph are suppressed.


        Unscaled[ezwf]: ym


       By default the graphs only contain the average values of the monitored
       variables - normally the transfer rates for incoming and outgoing traf-
       fic.  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.


        WithPeak[ezwf]: ym


       By default mrtg produces 4 graphs. With this option you can suppress
       the generation of selected graphs.  The option value syntax is analo-
       gous to the above two options.  In this example we suppress the yearly
       graph as it is quite empty in the beginning.


        Suppress[ezwf]: y


       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 (useful
       for getting a router name out of a database).


        Extension[ezwf]: phtml


       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

       XSize and YSize

       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

       XZoom and YZoom

       If you want your graphs to have larger pixels, you can "Zoom" them.


        XZoom[ezwf]: 2.0
        YZoom[ezwf]: 2.0

       XScale and YScale

       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

       YTics and YTicsFactor

       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 YTics-
       Factor.  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 con-
       stant factor, use this directive to define it ..


         Factor[as400]: 4096


       Change the default step from 5 * 60 seconds to something else (I have
       not tested this much ...)


        Step[ezwf]: 60


       When using rateup for graph generation, this will print the given title
       in the graph it generates.


        PNGTitle[ezwf]: WAN Link UK-US


       The Options Keyword allows you to set some boolean switches:

           The graph grows to the left by default.  This option flips the
           direction of growth causing the current time to be at the right
           edge of the graph and the history values to the left of it.

           All the monitored variable values are multiplied by 8 (i.e. shown
           in bits instead of bytes) ... looks much more impressive :-) It
           also affects the ’factory default’ labeling and units for the given

           All the monitored variable values are multiplied by 60 (i.e. shown
           in units per minute instead of units per second) in case of small
           values more accurate graphs are displayed.  It also affects the
           ’factory default’ labeling and units for the given target.

           All the monitored variable values are multiplied by 3600 (i.e.
           shown in units per hour instead of units per second) in case of
           small values more accurate graphs are displayed.  It also affects
           the ’factory default’ labeling and units for the given target.

           Suppress the information about uptime and device name in the gener-
           ated webpage.

           Don’t print usage percentages.

           Make the background of the generated gifs transparent.

           Print summary lines below graph as integers without commas.

           The relative percentage of IN-traffic to OUT-traffic is calculated
           and displayed in the graph as an additional line.  Note: Only a
           fixed scale is available (from 0 to 100%). Therefore if IN-traffic
           is greater than OUT-traffic then 100% is displayed.  If you suspect
           that your IN-traffic is not always less than or equal to your OUT-
           traffic you are urged to not use this options.  Note: If you use
           this option in combination with the Colours options, a fifth
           colour-name colour-value pair is required there.

           There are some ISPs who use the average Peak values to bill their
           customers.  Using this option MRTG displays these values for each
           graph. The value is built by averaging the max 5 minute traffic
           avarage for each ’step’ shown in the graph. For the Weekly graph
           this means that it builds the average of all 2 hour intervals 5
           minute peak values. (Confused? Thought so!)

           Treat the values gathered from target as ’current status’ measure-
           ments and not as ever incrementing counters.  This would be useful
           to monitor things like disk space, processor load, temperature, and
           the like ...

           In the absence of ’gauge’ or ’absolute’ options, MRTG treats vari-
           ables as a counters and calculates the difference between the cur-
           rent and the previous value and divides that by the elapsed time
           between the last two readings to get the value to be plotted.

           This is for counter type data sources which reset their value when
           they are read. This means that rateup does not have to build the
           difference between the current and the last value read from the
           data source. The value obtained is still divided by the elapsed
           time between the current and the last reading, which makes it dif-
           ferent from the ’gauge’ option. Useful for external data gatherers.

           Log unknown data as zero instead of the default behaviour of
           repeating the last value seen. Be careful with this, often a flat
           line in the graph is much more obvious than a line at 0.

           Normally we ignore all values which are zero when calculating the
           average transfer rate on a line. If this is not desirable use this

           If you are using rateup to log data, MRTG will create the graph
           images.  Normally these images have a shaded border around them. If
           you do not want the border to be drawn, enable this option. This
           option has no effect if you are not using rateup.

           As with the option above, this effects rateup graph generation
           only. Normally rateup will generate graphs with a small arrow show-
           ing the direction of the data. If you do not want this arrow to be
           drawn, enable this option. This option has no effect if you are not
           using rateup.

       noi When using rateup for graph generation, you can use this option to
           stop rateup drawing a graph for the ’I’ or first variable. This
           also removes entries for this variable in the HTML page MRTG
           generates, and will remove the peaks for this variable if they are
           enabled. This allows you to hide this data, or can be very useful
           if you are only graphing one line of data rather than two.  This
           option is not destructive - any data received for the the variable
           continued to be logged, it just isn’t shown.

       noo Same as above, except relating to the ’O’ or second variable.

           When using rateup for graph generation, this option disables MRTG
           adding the MRTG banner to the HTML pages it generates.

           When using rateup for graph generation, this option will stop MRTG
           from creating a legend at the bottom of the HTML pages it gener-

           When using rateup for graph generation, this option will print the
           router name in the graph it generates.  This option is overridden
           by the value of PNGTitle if one is given

           When using rateup for graph generation, this option will print a
           timestamp in the graph it generates, including a timezone if one is
           specified by the ’Timezone’ parameter.


        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.


        kilo[ezwf]: 1024


       Change the default multiplier prefixes (,k,M,G,T,P). In the tag Short-
       Legend 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, just
       put two consecutive commas.

       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:

           First variable (normally Input) on default graph.

           Second variable (normally Output) on default graph.

           Max first variable (input).

           Max second variable (output).

           2 digit hex values for Red, Green and Blue.


        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.


        Background[ezwf]: #a0a0a0a

       YLegend, ShortLegend, Legend[1234]

       The following keywords allow you to override the text displayed for the
       various legends of the graph and in the HTML document:

           The Y-axis label of the graph. Note that a text which is too long
           to fit in the graph will be silently ignored.

           The units string (default ’b/s’) used for Max, Average and Current

           The strings for the colour legend.


         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]: &nbsp;In:
         LegendO[ezwf]: &nbsp;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.


        Timezone[ezwf]: Japan

       The Timezone is the standard Solaris timezone, ie Japan, Hongkong, GMT,
       GMT+1 etc etc.


       By default, mrtg (actually rateup) uses the strftime(3) ’%W’ option to
       format week numbers in the monthly graphs.  The exact semantics of this
       format option vary between systems.  If you find that the week numbers
       are wrong, and your system’s strftime(3) routine supports it, you can
       try another format option.  The POSIX ’%V’ option seems to correspond
       to a widely used week numbering convention.  The week format character
       should be specified as a single letter; either W, V, or U.


        Weekformat[ezwf]: V


       This affects the creation of new rrd files. By default rrds are created
       to hold about 1 day’s worth of high resolution data. (plus 1 week of 30
       minute data, 2 months of 2 hour data and 2 years of 1 day data).  With
       this Keyword you can change the number of base interval entries config-
       ured for new rrds as they get created. Note that you must take the
       interval time into account.


        RRDRowCount[ezwf]: 1600


       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 (e.g. send email or a page to an

       Threshold checking is configured through the following parameters:

       ThreshDir (GLOBAL)

       By defining ThreshDir to point to a writable directory, MRTG will only
       alert you when a threshold boundery has been crossed.


        ThreshDir: /var/mrtg/thresh

       ThreshMinI  (PER TARGET)

       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.

       ThreshMaxI (PER TARGET)

       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.

       ThreshDesc (PER TARGET)

       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 user-friendly out-

       ThreshProgI  (PER TARGET)

       This defines a program to be run if ThreshMinI or ThreshMaxI is broken.
       MRTG passes 3 arguments: the $router variable, the threshold value bro-
       ken, and the current parameter value.

       ThreshProgOKI  (PER TARGET)

       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 argu-
       ments: the $router variable the unbroken threshold value, and the cur-
       rent parameter value.

       ThreshMinO, ThreshMaxO, ThreshProgO, and ThreshProgOKO

       These 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 threshold 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 which takes a series of environment variable
       assignments. Note that the quotes are mandatory. This does not work for
       external scripts. It is not possible to set environment variables per


        SetEnv[myrouter]:  EMAIL=""


       Pre- and Postfix

       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 Key-
       word 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


        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: ~

       Default Values

       The target name ’_’ specifies a default value for that Keyword. In the
       absence of explicit Keyword value, the prepended and the appended key-
       word 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’, spec-
       ify 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 previ-
       ous 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
        MaxBytes[_]: 8000
        Title[]: Traffic Analysis for IF 2

       The default MaxBytes for the target in the
       above example will be 1250000, which was in effect where the target
       name first appeared in the config file.


       --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 configura-
           tion-file appended with "_l").

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

       --logging filenameeventlog
           If this is set to writable filename, all output from mrtg (warn-
           ings, debug messages, errors) will go to filename. If you are run-
           ning 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, complaing about the fact that
           mrtg has no message dll. If any of the Windows folks want to con-
           tribute one, they are welcome.

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

           Define the name and path of the pid file for mrtg running as a dae-

           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




       Minimal mrtg.cfg

        WorkDir: /usr/tardis/pub/www/stats/mrtg
        MaxBytes[r1]: 8000
        Title[r1]: Traffic Analysis ISDN
        PageTop[r1]: <H1>Stats for our ISDN Line</H1>

       Cfg for several Routers.

        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>

        Title[backb]: our Campus Backbone
        PageTop[backb]: our Campus Backbone</H1>
        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>


       Tobias Oetiker <> and many contributors

2.10.5                            2003-09-11                      REFERENCE(1)

Man(1) output converted with man2html