MRTG-REFERENCE(1)              mrtg             MRTG-REFERENCE(1)



NNAAMMEE
       mrtg-reference - MRTG 2.13.0 configuration reference

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

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

SSYYNNTTAAXX
       MRTG configuration file syntax follows some simple rules:

       +o   Keywords must start at the beginning of a line.

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

       +o   Empty Lines are ignored

       +o   Lines starting with a # sign are comments.

       +o   You can add other files into the configuration file
           using

           IInncclluuddee:: _f_i_l_e

           Example:

            Include: base-options.inc

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

GGLLOOBBAALL KKEEYYWWOORRDDSS
       WWoorrkkDDiirr

       WorkDir specifies where the logfiles and the webpages
       should be created.

       Example:

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

OOPPTTIIOONNAALL GGLLOOBBAALL KKEEYYWWOORRDDSS
       HHttmmllDDiirr

       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.

       Example:

        Htmldir: /www/mrtg/



       IImmaaggeeDDiirr

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

       Example:

        Imagedir: /www/mrtg/images

       LLooggDDiirr

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

       Example:

        Logdir: /www/mrtg/logs

       FFoorrkkss ((UUNNIIXX oonnllyy))

       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.

       Example:

        Forks: 4

       EEnnaabblleeIIPPvv66

       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 _I_P_v_4_O_n_l_y per target option for these
       routers.

       IPv6 is disabled by default.

       Example:

        EnableIPv6: Yes





       EEnnaabblleeSSnnmmppVV33

       When set to yes, uses the Net::SNMP module instead of the
       SNMP_SESSION module for generating snmp queries.  This
       allows the use of SNMPv3 if other snmpv3 parameters are
       set.

       SNMPv3 is disabled by default.

       Example:

        EnableSnmpV3: yes

       RReeffrreesshh

       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).

       Example:

        Refresh: 600

       IInntteerrvvaall

       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:

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

       +o   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 minutes. If you are calling mrtg every 5 minutes,
       you can leave this line commented out.

       Example:

        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, set-
       ting 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.

       MMaaxxAAggee

       MRTG relies heavily on the real time clock of your com-
       puter. If the time is set to a wrong value, especially if
       it is advanced far into the future, this will cause mrtg
       to expire lots of supposedly old data from the log files.

       To prevent this, you can add a 'reasonability' check by
       specifying a maximum age for log files. If a file seems to
       be older, mrtg will not touch it but complain instead,
       giving you a chance to investigate the cause.

       Example:

        MaxAge: 7200

       The example above will make mrtg refuse to update log
       files older than 2 hours (7200 seconds).

       WWrriitteeEExxppiirreess

       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

       Example:

        WriteExpires: Yes

       NNooMMiibb22

       Normally we ask the SNMP device for 'sysUptime' and 'sys-
       Name' properties.  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 management of a system.

       Example:

        NoMib2: Yes

       SSiinngglleeRReeqquueesstt

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

       Examples

        SingleRequest: Yes

       SSnnmmppOOppttiioonnss

       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 supported:

        timeout                   => $default_timeout,
        retries                   => $default_retries,
        backoff                   => $default_backoff,
        default_max_repetitions   => $max_repetitions,
        use_16bit_request_ids     => 1,
        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.

       A per-target SnmpOptions[] keyword will override the
       global settings.  That keyword is primarily for SNMPv3.

       The 16bit request ids are the only way to query the broken
       SNMP implementation of SMC Barricade routers.

       Example:

        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.

       IIccoonnDDiirr

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

       Example:

        IconDir: /mrtgicons/

       LLooaaddMMIIBBss

       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 WorkDir.

       Example:

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

       LLaanngguuaaggee

       Switch output format to the selected Language (Check the
       _t_r_a_n_s_l_a_t_e 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 rus-
       sian russian1251 serbian slovak slovenian spanish swedish
       turkish ukrainian

       Example:

        Language: danish

       LLooggFFoorrmmaatt

       Setting LogFormat to 'rrdtool' in your mrtg.cfg file
       enables rrdtool mode.  In rrdtool mode, mrtg relies on
       rrrrddttooooll to do its logging. See mrtg-rrd.

       Example:

        LogFormat: rrdtool

       LLiibbAAdddd

       If you are using rrdtool mode and your rrrrddttooooll 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 appro-
       priate path.

       Example:

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

       PPaatthhAAdddd

       If the rrrrddttooooll executable can not be found in the normal
       "PATH", you can use this keyword to add a suitable direc-
       tory to your path.

       Example:

        PathAdd: /usr/local/rrdtool/bin/

       RRuunnAAssDDaaeemmoonn

       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 configura-
       tion 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 ----uusseerr==_u_s_e_r___n_a_m_e and ----ggrroouupp==_g_r_o_u_p___n_a_m_e 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 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.

       Example

        RunAsDaemon: Yes
        Interval:    5

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

       If you are daemontools and still want to run mrtg as a
       daemon you can additionally specify

        NoDetach:     Yes

       this will make mrtg run but without detaching it from the
       terminal.

       CCoonnvveerrssiioonnCCooddee

       Some devices may produce non-numeric values that would
       nevertheless be useful to graph with MRTG if those values
       could be converted to numbers.  The ConversionCode keyword
       specifies the path to a file containing Perl code to per-
       form 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 subroutine must return an undefined
       value if the conversion fails. In case of failure, a warn-
       ing 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 declaration 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 arbitrarily named "MyCon-
       versions.pl" 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 con-
       figuration file (assuming that the conversion code file is
       saved in the mrtg/bin directory along with mrtg itself):

        ConversionCode: MyConversions.pl

       This will cause MRTG to include the definition of the sub-
       routine Length2Int in its execution environment.
       Length2Int can then be invoked on any target by appending
       "|Length2Int" to the target definition as follows:

        Target[myrouter]: 1.3.6.1.4.1.999.1&1.3.6.1.4.1.999.1:public@mydevice|Length2Int

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

PPEERR TTAARRGGEETT CCOONNFFIIGGUURRAATTIIOONN
       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.

       TTaarrggeett

       With the _T_a_r_g_e_t keyword you tell mrtg what it should moni-
       tor. The _T_a_r_g_e_t keyword takes arguments in a wide range of
       formats:

       Basic
           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.

           Example:

            Target[myrouter]: 2:public@wellfleet-fddi.ethz.ch

           If your community contains a "@" or a " " these char-
           acters must be escaped with a "\".

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

       SNMPv2c
           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 nor-
           mal 32 bit.

           Example:

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

       SNMPv3
           As an alternative to SNMPv2c, SNMPv3 provides access
           to the ifHC* counters, along with encryption.  Not all
           devices support SNMPv3, and you will also need the
           perl Net::SNMP library in order to use it.  It is rec-
           ommended that cfgmaker be used to generate configura-
           tions involving SNMPv3, as it will check if the
           Net::SNMP library is loadable, and will switch to
           SNMPv2c if v3 is unavailable.

           SNMP v3 requires additional authentication parameters,
           passed using the SnmpOptions[] per-target keyword.

           Example:
             Target[myrouter]: 2:router1:::::3
             SnmpOptions[myrouter]: username=>'user1'

       Reversing
           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 "Tar-
           get" description. It flips the incoming and outgoing
           traffic rates.

           Example:

            Target[ezci]: -1:public@ezci-ether.ethz.ch

       Explicit OIDs
           You can also explicitly define which OID to query by
           using the following syntax 'OID_1&OID_2:commu-
           nity@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.

           Example:

            Target[myrouter]: 1.3.6.1.2.1.2.2.1.14.1&1.3.6.1.2.1.2.2.1.20.1:public@myrouter

       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 ifInErrors and ifOutErrors.  This
           means you can specify the above as:

           Example:

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

       SnmpWalk
           It may be that you want to monitor an snmp object that
           is only reachable by 'walking'. You can get mrtg to
           walk by prepending the OID with the string WWaaLLKK or if
           you want a particular entry from the table returned by
           the walk you can use WWaaLLKK_x where _x is a number start-
           ing from 0 (!).

           Example:

             Target[myrouter]: WaLKstrangeOid.1&WaLKstrangeOid.2:public@myrouter

             Target[myrouter]: WaLK3strangeOid.1&WaLK4strangeOid.2: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 off-
           set, causing MRTG to graphs wrong instances etc.  MRTG
           supports IP address instead of ifindex in target defi-
           nition. 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 dif-
           ferent OIDs and/or interface split by '&' delimiter.

           You can tell cfgmaker to generate such references with
           the option ----iiffrreeff==iipp.

           Example:

            Target[myrouter]: /1.2.3.4:public@wellfleet-fddi.ethz.ch
            Target[ezci]: -/1.2.3.4:public@ezci-ether.ethz.ch
            Target[myrouter]: 1.3.6.1.2.1.2.2.1.14/1.2.3.4&1.3.6.1.2.1.2.2.1.14/1.2.3.4:public@myrouter
            Target[myrouter]: ifInErrors/1.2.3.4&ifOutErrors/1.2.3.4:public@myrouter

       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 ----iiffrreeff==ddeessccrr.

           Example:

            Target[myrouter]: \My-Interface2:public@wellfleet-fddi.ethz.ch
            Target[ezci]: -\My-Interface2:public@ezci-ether.ethz.ch
            Target[myrouter]: 1.3.6.1.2.1.2.2.1.14\My-Interface2&1.3.6.1.2.1.2.2.1.14\My-Interface3:public@myrouter
            Target[myrouter]: 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[myrouter]: \fun\:\ ney\&ddd:public@hello.router

       Interface by Name
           This is the only sensible way to reference the inter-
           faces of your switches.

           You can tell cfgmaker to generate such references with
           the option ----iiffrreeff==nnaammee.

           Example:

            Target[myrouter]: #2/11:public@wellfleet-fddi.ethz.ch
            Target[ezci]: -#2/11:public@ezci-ether.ethz.ch
            Target[myrouter]: 1.3.6.1.2.1.2.2.1.14#3/7&1.3.6.1.2.1.2.2.1.14#3/7:public@myrouter
            Target[myrouter]: 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[myrouter]: #\:\ 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 Physi-
           cal 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 tar-
           get 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 identifica-
           tion. 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 ----iiffrreeff==eetthh.

           Example:

            Target[myrouter]: !0a-0b-0c-0d:public@wellfleet-fddi.ethz.ch
            Target[ezci]: -!0-f-bb-05-71-22:public@ezci-ether.ethz.ch
            Target[myrouter]: 1.3.6.1.2.1.2.2.1.14!0a-00-10-23-44-51&!0a-00-10-23-44-51:public@myrouter
            Target[myrouter]: 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 constant 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 ----iiffrreeff==ttyyppee.

           Example:

            Target[myrouter]: %13:public@wellfleet-fddi.ethz.ch
            Target[ezci]: -%13:public@ezci-ether.ethz.ch
            Target[myrouter]: 1.3.6.1.2.1.2.2.1.14%13&1.3.6.1.2.1.2.2.1.14%14:public@myrouter
            Target[myrouter]: 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 commu-
           nication using colon-separated 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
           follows:

            community@router[:[port][:[timeout][:[retries][:[backoff][:[version]][|name]]]]]

           where the meaning of each parameter is as follows:

           port
               the UDP port under which to contact the SNMP agent
               (default: 161)

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

           retries
               number of times a timed-out request will be
               retried (default: 5)

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

           version
               for SNMP version. If you have a fast router you
               might want to put a '2' here.  For authenticated
               or encrypted SNMP, you can try to put a '3' here.
               This will make mrtg try to poll the 64 bit coun-
               ters and thus prevent excessive counter wrapping.
               Not all routers support this though.  SNMP v3
               requires additional setup, see SnmpOptions[] for
               full details.

               Example:

                3:public@router1:::::2

           name
               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.

               Example:

                1.3.6.1.4.1.999.1&1.3.6.1.4.1.999.2:public@mydevice:161::::2|Length2Int

               This would retrieve values from the OID
               1.3.6.1.4.1.999.1 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.

           Example:

             Target[ezci]: 1:public@ezci-ether.ethz.ch:9161::4

           This would refer to the input/output octet counters
           for the interface with _i_f_I_n_d_e_x _1 on
           _e_z_c_i_-_e_t_h_e_r_._e_t_h_z_._c_h, as known by the SNMP agent listen-
           ing 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.

           Example:

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

       External Monitoring Scripts
           If you want to monitor something which does not pro-
           vide 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 count'

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

           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 _O_p_t_i_o_n_s keyword.

           Example:

            Target[myrouter]: `/usr/local/bin/df2mrtg /dev/dsk/c0t2d0s0`

           Note the use of the backticks (`), not apostrophes (')
           around the command.

           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 capac-
           ity.

           Examples:

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

            Target[myrouter]: 1.3.6.1.4.1.999.1&1.3.6.1.4.1.999.2:public@mydevice /
                1.3.6.1.4.1.999.3&1.3.6.1.4.1.999.4:public@mydevice * 100

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

           MRTG automatically rounds the result of the expression
           to an integer 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 preci-
           sion. 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 collection and
           uses the collected data for each instance of a partic-
           ular target. Recognition of two target definitions as
           being identical is based on a simple string match
           rather than any kind of deeper semantic analysis.

           Example:

            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:public@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 1:pub-
           lic@CiscoA.

       MMaaxxBByytteess

       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 _M_a_x_B_y_t_e_s is returned, it is
       ignored.  Also read the section on _A_b_s_M_a_x for further
       info.  The _M_a_x_B_y_t_e_s value is also used in calculating the
       Y range for unscaled graphs (see the section on _U_n_s_c_a_l_e_d).

       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, 10 MB Ethernet = 1250000, 100 MB
       Ethernet = 12500000. The _M_a_x_B_y_t_e_s 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 mon-
       itored variables, you can use MaxBytes1 and MaxBytes2
       instead of MaxBytes.

       Example:

        MaxBytes[myrouter]: 1250000

       TTiittllee

       Title for the HTML page which gets generated for the
       graph.

       Example:

        Title[myrouter]: Traffic Analysis for Our Nice Company

OOPPTTIIOONNAALL PPEERR TTAARRGGEETT KKEEYYWWOORRDDSS
       PPaaggeeTToopp

       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.

       Example:

        PageTop[myrouter]: <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.

       RRoouutteerrUUppttiimmee

       In cases where you calculate the used bandwidth from sev-
       eral 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 com-
       munity and address again with the _R_o_u_t_e_r_U_p_t_i_m_e keyword.

       Example:

        Target[kacisco.comp.edu]: 1:public@194.64.66.250 + 2:public@194.64.66.250
        RouterUptime[kacisco.comp.edu]: public@194.64.66.250

       RRoouutteerrNNaammee

       If the default name of the router is incorrect/uninforma-
       tive, you can use RouterName to specify a different OID on
       either the same or a different 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
       1.3.6.1.4.1.4779.1.1.3.0, so we can have MRTG display this
       instead of sysName.

       Example:

        RouterName[kacisco.comp.edu]: 1.3.6.1.4.1.4779.1.1.3.0

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

        RouterName[kacisco.comp.edu]: 1.3.6.1.4.1.4779.1.1.3.0:public@194.64.66.251

       MMaaxxBByytteess11

       Same as MaxBytes, for variable 1.

       MMaaxxBByytteess22

       Same as MaxBytes, for variable 2.

       IIPPvv44OOnnllyy

       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 tar-
       get, 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 enabled.

       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.

       Example:

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

       SSnnmmppOOppttiioonnss ((VV33))

       SNMPv3 requires a fairly rich set of options.  This per-
       target keyword allows access to the User Security Model of
       SNMPv3.  Options are listed in the same syntax as a perl
       hash.

       _S_e_c_u_r_i_t_y _M_o_d_e_s

       SNMPv3 has three security modes, defined on the device
       being polled.  For example, on Cisco routers the security
       mode is defined by the snmp-server group global configura-
       tion command.

       NoAuthNoPriv
           Neither Authentication nor Privacy is defined.  Only
           the Username option is specified for this mode.

           Example:

            SnmpOptions[myrouter]: username=>'user1'

       AuthNoPriv
           Uses a Username and a password.  The password can be
           hashed using the snmpkey application, or passed in
           plain text along with the ContextEngineID

           Example:

            SnmpOptions[myrouter]: username=>'user1',authpassword=>'example',
              contextengineid=>'80000001110000004000000'

       Priv
           Both Authentication and Privacy is defined.  The
           default privacy protocol is des.

           Example:
            SnmpOptions[myrouter]:
           authkey=>'0x1e93ab5a396e2af234c8920e61cfe2028072c0e2',
              authprotocol=>'sha',privprotocol=>'des',user-
           name=>'user1',
              privkey=>'0x498d74940c5872ed387201d74b9b25e2'

       _s_n_m_p _o_p_t_i_o_n_s

       The following option keywords are recognized:

       username
           The user associated with the User Security Model

       contextname
           An SNMP agent can define multiple contexts.  This key-
           word allows them to be polled.

       contextengineid
           A unique 24-byte string identifying the snmp-agent.

       authpassword
           The plaintext password for a user in either AuthNoPriv
           or Priv mode.

       authkey
           A md5 or sha hash of the plain-text password, along
           with the engineid.  Use the snmpkey commandline pro-
           gram to generate this hash, or use Net::SNMP::Secu-
           rity::USM in a script.

       authprotocol {sha|md5}
           The hashing algorithm defined on the SNMP client.
           Defaults to md5.

       privpassword
           A plaintext pre-shared key for encrypting snmp packets
           in Priv mode.

       privkey
           A hash of the plain-text pre-shared key, along with
           the engineid.  Use the snmpkey commandline program to
           generate this hash, or use Net::SNMP::Security::USM in
           a script.

       privprotocol {des|3desede|aescfb128|aescfb192|aescfb256}
           Specifies the encryption method defined on the snmp
           agent.  The default is des.

       PPaaggeeFFoooott

       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:

       Example:

        PageFoot[myrouter]: Contact <A HREF="mailto:peter@x.yz">Peter</A>
         if you have questions regarding this page

       AAddddHHeeaadd

       Use this tag like the _P_a_g_e_T_o_p header, but its contents
       will be added between </TITLE> and </HEAD>.

       Example:

        AddHead[myrouter]: <link rev="made" href="mailto:mrtg@blabla.edu">

       BBooddyyTTaagg

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

       Example:

        BodyTag[myrouter]: <BODY LEFTMARGIN="1" TOPMARGIN="1"
                             BACKGROUND="/stats/images/bg.neo2.gif">

       AAbbssMMaaxx

       If you are monitoring a link which can handle more traffic
       than the _M_a_x_B_y_t_e_s value. Eg, a line which uses compression
       or some frame relay link, you can use the _A_b_s_M_a_x 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 _A_b_s_M_a_x, rateup
       will ignore values higher than _M_a_x_B_y_t_e_s.

       Example:

        AbsMax[myrouter]: 2500000

       UUnnssccaalleedd

       By default each graph is scaled vertically to make the
       actual data visible even when it is much lower than
       _M_a_x_B_y_t_e_s.  With the _U_n_s_c_a_l_e_d 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.  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.

       Example:

        Unscaled[myrouter]: ym

       WWiitthhPPeeaakk

       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.

       Examples:

        WithPeak[myrouter]: ym

       SSuupppprreessss

       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.

       Example:

        Suppress[myrouter]: y

       EExxtteennssiioonn

       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).

       Example:

        Extension[myrouter]: phtml



       DDiirreeccttoorryy

       By default, mrtg puts all the files that it generates for
       each target (the GIFs, the HTML page, the log file, etc.)
       in _W_o_r_k_D_i_r.

       If the _D_i_r_e_c_t_o_r_y option is specified, the files are
       instead put into a directory under _W_o_r_k_D_i_r or Log-, Image-
       and HtmlDir).  (For example the _D_i_r_e_c_t_o_r_y option below
       would cause all the files for a target myrouter to be put
       into directory /usr/tardis/pub/www/stats/mrtg/myrouter/ .)

       The directory must already exist; mrtg will not create it.

       Example:

        WorkDir: /usr/tardis/pub/www/stats/mrtg
        Directory[myrouter]: myrouter

       NOTE: the Directory option must always be 'relative' or
       bad things will happen.

       XXSSiizzee aanndd YYSSiizzee

       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

       Example:

        XSize[myrouter]: 300
        YSize[myrouter]: 300

       XXZZoooomm aanndd YYZZoooomm

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

       Example:

        XZoom[myrouter]: 2.0
        YZoom[myrouter]: 2.0

       XXSSccaallee aanndd YYSSccaallee

       If you want your graphs to be actually scaled use _X_S_c_a_l_e
       and _Y_S_c_a_l_e. (Beware: while this works, the results look
       ugly (to be frank) so if someone wants to fix this:
       patches are welcome.

       Example:

        XScale[myrouter]: 1.5
        YScale[myrouter]: 1.5

       YYTTiiccss aanndd YYTTiiccssFFaaccttoorr

       If you want to show more than 4 lines per graph, use
       YTics.  If you want to scale the value used for the YLe-
       gend of these tics, use YTicsFactor.  The default value
       for YTics is 4 and the default value for YTicsFactor is
       1.0 .

       Example:

       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[myrouter]: 7
         YTicsFactor[myrouter]: 0.01

       FFaaccttoorr

       If you want to multiply all numbers shown below the graph
       with a constant factor, use this directive to define it ..

       Example:

         Factor[as400]: 4096

       SStteepp

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

       Example:

        Step[myrouter]: 60

       PPNNGGTTiittllee

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

       Example:

        PNGTitle[myrouter]: WAN Link UK-US

       OOppttiioonnss

       The _O_p_t_i_o_n_s Keyword allows you to set some boolean
       switches:

       growright
           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.

       bits
           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 target.

       perminute
           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.

       perhour
           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.

       noinfo
           Suppress the information about uptime and device name
           in the generated webpage.

       nopercent
           Don't print usage percentages.

       transparent
           Make the background of the generated gifs transparent.

       integer
           Print summary lines below graph as integers without
           commas.

       dorelpercent
           The relative percentage of IN-traffic to OUT-traffic
           is calculated and displayed in the graph as an addi-
           tional 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 sus-
           pect 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 combi-
           nation with the _C_o_l_o_u_r_s options, a fifth colour-name
           colour-value pair is required there.

       avgpeak
           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 average for each
           'step' shown in the graph. For the Weekly graph this
           means that it builds the average of all 2 hour inter-
           vals 5 minute peak values. (Confused? Thought so!)

       gauge
           Treat the values gathered from target as 'current sta-
           tus' measurements and not as ever incrementing coun-
           ters.  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 variables as a counters and calculates the dif-
           ference between the current and the previous value and
           divides that by the elapsed time between the last two
           readings to get the value to be plotted.

       absolute
           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 cur-
           rent 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 different from the 'gauge' option. Useful for
           external data gatherers.

       derive
           If you are using rrdtool as logger/grapher you can use
           a third type of data source. Derive is like counter,
           except that it is not required to go UP all the time.
           It is useful for situations where the change of some
           value should be graphed.

       unknaszero
           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.

       withzeroes
           Normally we ignore all values which are zero when cal-
           culating the average transfer rate on a line. If this
           is not desirable use this option.

       noborder
           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.

       noarrow
           As with the option above, this effects rateup graph
           generation only. Normally rateup will generate graphs
           with a small arrow showing 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.

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

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

       printrouter
           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

       pngdate
           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 'Time-
           zone' parameter.

       logscale
           The llooggssccaallee option causes rateup to display the data
           with the Y axis scaled logarithmically.  Doing so
           allows the normal traffic to occupy the majority of
           the vertical range, while still showing any spikes at
           their full height.

           llooggssccaallee displays all the available data and will
           always produce well-behaved graphs.  People often con-
           sider a logarithmically scaled graph counterintuitive,
           however, and thus hard to interpret.

       secondmean
           The sseeccoonnddmmeeaann option sets the maximum value on the
           graph to the mean of the data greater than the mean of
           all data.  This produces a graph that focuses more on
           the typical data, while clipping large peaks.

           Using sseeccoonnddmmeeaann will give a more intutive linearly
           scaled graph, but can result in a uselessly high or
           low scale in some rare situations (specifically, when
           the data includes a large portion of values far from
           the actual mean)

           If a target includes both llooggssccaallee and sseeccoonnddmmeeaann in
           the options, the sseeccoonnddmmeeaann takes precedence.

       Example:

        Options[myrouter]: growright, bits

       kkiilloo

       Use this option to change the multiplier value for build-
       ing prefixes. Defaultvalue is 1000. This tag is for the
       special case that 1kB = 1024B, 1MB = 1024kB and so far.

       Example:

        kilo[myrouter]: 1024

       kkMMGG

       Change the default multiplier prefixes (,k,M,G,T,P). In
       the tag _S_h_o_r_t_L_e_g_e_n_d 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) dis-
       played in nm/h.

        ShortLegend[myrouter]: m/h
        kMG[myrouter]: n,u,m,,k,M,G,T,P
        options[myrouter]: perhour

       CCoolloouurrss

       The _C_o_l_o_u_r_s tag allows you to override the default colour
       scheme.  Note: All 4 of the required colours must be spec-
       ified here. The colour name ('Colourx' below) is the leg-
       end 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 _d_o_r_e_l_p_e_r_c_e_n_t options tag a fifth
       colour name colour value pair is required:
       Col1#RRGGBB,Col2#RRGGBB,Col3#RRGGBB,Col4#RRGGBB,Col5#RRGGBB

       Colour1
           First variable (normally Input) on default graph.

       Colour2
           Second variable (normally Output) on default graph.

       Colour3
           Max first variable (input).

       Colour4
           Max second variable (output).

       RRGGBB
           2 digit hex values for Red, Green and Blue.

       Example:

        Colours[myrouter]: GREEN#00eb0c,BLUE#1000ff,DARK GREEN#006600,VIOLET#ff00ff

       BBaacckkggrroouunndd

       With the _B_a_c_k_g_r_o_u_n_d tag you can configure the background
       colour of the generated HTML page.

       Example:

        Background[myrouter]: #a0a0a0a

       YYLLeeggeenndd,, SShhoorrttLLeeggeenndd,, LLeeggeenndd[[11223344]]

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

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

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

       Legend[1234IO]
           The strings for the colour legend.

       Example:

         YLegend[myrouter]: Bits per Second
         ShortLegend[myrouter]: b/s
         Legend1[myrouter]: Incoming Traffic in Bits per Second
         Legend2[myrouter]: Outgoing Traffic in Bits per Second
         Legend3[myrouter]: Maximal 5 Minute Incoming Traffic
         Legend4[myrouter]: Maximal 5 Minute Outgoing Traffic
         LegendI[myrouter]: &nbsp;In:
         LegendO[myrouter]: &nbsp;Out:

       Note, if _L_e_g_e_n_d_I or _L_e_g_e_n_d_O are set to an empty string
       with

        LegendO[myrouter]:

       The corresponding line below the graph will not be printed
       at all.

       TTiimmeezzoonnee

       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.

       Example:

        Timezone[myrouter]: Japan

       The Timezone is the standard timezone of your system, ie
       Japan, Hongkong, GMT, GMT+1 etc etc.

       WWeeeekkffoorrmmaatt

       By default, mrtg (actually rateup) uses the _s_t_r_f_t_i_m_e(3)
       '%V' 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 _s_t_r_f_t_i_m_e(3) routine supports it, you can try
       another format option.  The POSIX '%V' option correspond
       to the widely used ISO 8601 week numbering standard.  The
       week format character should be specified as a single let-
       ter; either W, V, or U.

       The UNIX version of rateup uses the libc implementation of
       strftime.  On Windows, the native strftime implementation
       does not know about %V. So there we use a different imple-
       mentation of strftime that does support %V.

       Example:

        Weekformat[myrouter]: W

       RRRRDDRRoowwCCoouunntt

       This affects the creation of new rrd files. By default
       rrds are created to hold about 1 day's worth of high reso-
       lution 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.

       Example:

        RRDRowCount[myrouter]: 1600

       TTiimmeeSSttrrPPooss

       This defines placement of the timestamp string on the
       image. Possible values are RU, LU, RL, LL (which stand,
       respectively, for RightUpper, LeftUpper, RightLower and
       LeftLower corner) and NO (for no timestamp).  By default,
       no timestamp is placed on the image.

       Example:

        TimeStrPos[myrouter]: RU



       TTiimmeeSSttrrFFmmtt

       Using this keyword you may specify format of the timestamp
       to be placed on the image (if enabled by the TimeStrPos
       keyword). Specified string will be used by the _s_t_r_f_t_i_m_e_(_)
       function - see _s_t_r_f_t_i_m_e(3) documentation for conversion
       specifiers available on your system.  Default format:
       %Y-%m-%d %H:%M

       Example:

        TimeStrFmt[myrouter]: %H:%M:%S

TTHHRREESSHHOOLLDD CCHHEECCKKIINNGG
       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 administrator).

       Threshold checking is configured through the following
       parameters:

       TThhrreesshhDDiirr ((GGLLOOBBAALL))

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

       Example:

        ThreshDir: /var/mrtg/thresh

       TThhrreesshhMMiinnII  ((PPEERR TTAARRGGEETT))

       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.

       TThhrreesshhMMaaxxII ((PPEERR TTAARRGGEETT))

       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.

       TThhrreesshhDDeesscc ((PPEERR TTAARRGGEETT))

       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 output.

       TThhrreesshhPPrrooggII  ((PPEERR TTAARRGGEETT))

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





       TThhrreesshhPPrrooggOOKKII  ((PPEERR TTAARRGGEETT))

       This defines a program to be run if the parameter is cur-
       rently 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 unbroken threshold value, and the current parameter
       value.

       TThhrreesshhMMiinnOO,, TThhrreesshhMMaaxxOO,, TThhrreesshhPPrrooggOO,, aanndd TThhrreesshhPPrrooggOOKKOO

       These work the same as their *I counterparts, except on
       the Output (second) parameter.

       _N_o_t_e _t_h_a_t _y_o_u _c_a_n _u_s_e _t_h_e _S_e_t_E_n_v _p_a_r_a_m_e_t_e_r _e_x_p_l_a_i_n_e_d _a_b_o_v_e
       _t_o _p_a_s_s _a_d_d_i_t_i_o_n_a_l _i_n_f_o_r_m_a_t_i_o_n _t_o _t_h_e _t_h_r_e_s_h_o_l_d _p_r_o_g_r_a_m_s_.

       SSeettEEnnvv

       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 target.

       Example:

        SetEnv[myrouter]:  EMAIL="contact_email@someplace.net"
                           HOST="www.some_server.net"

PPEERR TTAARRGGEETT DDEEFFAAUULLTT VVAALLUUEESS
       PPrree-- aanndd PPoossttffiixx

       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-val-
       ued 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 com-
       mon contact person in all the pages generated from targets
       defined later in this file.

       Example:

        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.:

        PageTop[^]:
        PageTop[$]:





       NNooSSppaacceeCChhaarr

       With PREPEND and APPEND (see below) 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 global option _N_o_S_p_a_c_e_C_h_a_r to define a character which
       can be mentioned at the end of a $ or ^ definition in
       order to supress the space.

       Example:

         NoSpaceChar: ~
         Target[^]: 1.3.6.1.4.1.482.50.2.4.20.0&1.3.6.1.4.1.482.50.2.4.21.0:get@~
         Target[a]: a.tolna.net
         Target[b]: b.tolna.net
         Target[c]: c.tolna.net
         Target[d]: d.tolna.net

       DDeeffaauulltt VVaalluueess

       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.

       Example:

        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.:

        YLegend[_]:

       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.

       Example:

        MaxBytes[_]: 1250000
        Target[myrouter.somplace.edu.2]: 2:public@myrouter.somplace.edu
        MaxBytes[_]: 8000
        Title[myrouter.somplace.edu.2]: Traffic Analysis for myrouter.somplace.edu IF 2

       The default _M_a_x_B_y_t_e_s for the target myrouter.some-
       place.edu.2 in the above example will be 1250000, which
       was in effect where the target name myrouter.some-
       place.edu.2 first appeared in the config file.

CCOOMMMMAANNDD LLIINNEE OOPPTTIIOONNSS
       ----uusseerr _u_s_e_r_n_a_m_e  and ----ggrroouupp _g_r_o_u_p_n_a_m_e
           Run as the given user and/or group. (Unix Only)

       ----lloocckk--ffiillee _f_i_l_e_n_a_m_e
           Use an alternate lock-file (the default is to use the
           configuration-file appended with "_l").

       ----ccoonnffccaacchhee--ffiillee _f_i_l_e_n_a_m_e
           Use an alternate confcache-file (the default is to use
           the configuration-file appended with ".ok")

       ----llooggggiinngg _f_i_l_e_n_a_m_e|eevveennttlloogg
           If this is set to writable filename, all output from
           mrtg (warnings, debug messages, errors) will go to
           _f_i_l_e_n_a_m_e. If you are running on Win32 you can specify
           eevveennttlloogg instead of a filename which will send all
           error to the windows event log.

           NNOOTTEE:: Note, there is no Message DLL for mrtg included
           with 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 you go to the mrtg contrib
           download area (on the website) you will find the
           mrtg-message-dll.zip which does contain such a thing.

       ----ddaaeemmoonn
           Put MRTG into the background, running as a daemon.
           This works the same way as the config file option, but
           the switch is required for proper FHS operation
           (because /var/run is writable only by root)

       ----ffhhss
           Configure all mrtg paths to conform to the FHS speci-
           fication; http://www.pathname.com/fhs/

       ----cchheecckk
           Only check the cfg file for errors. Do not do any-
           thing.

       ----ppiidd--ffiillee==ss
           Define the name and path of the pid file for mrtg run-
           ning as a daemon

       ----ddeebbuugg==ss
           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
            coca - confcache operations
            fork - forking view
            time - some timing info
            log  - logging of data via rateup or rrdtool

           Example:

            --debug="cfg,snpo"

EEXXIITT CCOODDEESS
       An exit code of 0 indicates that all targets were success-
       ful.  Generally speaking, most codes greater than 0 indi-
       cate that there was an unrecoverable problem.  One excep-
       tion to this is code 91, which indicates that at least one
       of the targets was succesful.  A partial listing of the
       codes follows:

         0: All targets sucessful

         2: Config error (can't read, fatal error in config, etc)
        17: Another MRTG process is processing config

        91: At least one target sucessful
        92: No targets were sucessful

EEXXAAMMPPLLEESS
       MMiinniimmaall mmrrttgg..ccffgg

        WorkDir: /usr/tardis/pub/www/stats/mrtg
        Target[r1]: 2:public@myrouter.somplace.edu
        MaxBytes[r1]: 8000
        Title[r1]: Traffic Analysis ISDN
        PageTop[r1]: <H1>Stats for our ISDN Line</H1>

       CCffgg ffoorr sseevveerraall RRoouutteerrss..

        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:public@router.somplace.edu

        Title[backb]: our Campus Backbone
        PageTop[backb]: our Campus Backbone</H1>
        Target[backb]: 1:public@router.somplace.edu
        MaxBytes[backb]: 1250000

        # the following line removes the default prepend value
        # defined above

        Title[^]:

        Title[isdn2]: Traffic for the Backup ISDN Line
        PageTop[isdn2]: our ISDN Line</H1>
        Target[isdn2]: 3:public@router.somplace.edu

AAUUTTHHOORR
       Tobias Oetiker <oetiker@ee.ethz.ch> and many contributors



2.13.0                      2006-01-29          MRTG-REFERENCE(1)
