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



NNAAMMEE
       mrtg-reference - MRTG 2.17.2 configuration reference

OOVVEERRVVIIEEWW
       The runtime behaviour of MRTG is governed by a configuration file.
       Run-of-the-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.  The current working
           directory will be searched first.

           If the included filename contains an asterisk, then this is taken
           as a wildcard for zero or more characters, and all matching files
           are included.  Thus, you can use this statement to include all
           files in a specified subdirectory.

           Example:

            Include: servers/*.cfg

           In this case, you should be very careful that your wildcard pattern
           does not find a match relative to the current working directory if
           you mean it to be relative to the main config file directory, since
           the working directory is checked for a match first (as with a
           normal Include directive).  Therefore, use of something like '*/*'
           is discouraged.

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 in the
       format

        Interval: MM[:SS]

       Down to 1 second. 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. Also note that you must
       make sure that your mrtg-rrd Web-frontend can deal with this kind of
       Interval setting.

   MMaaxxAAggee
       MRTG relies heavily on the real time clock of your computer. 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 'sysName'
       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 asking for
       multiple snmp variables in one go. Set this in your cfg file to force
       mrtg to only ask for one variable per request.

       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 variable 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 russian 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 appropriate 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 directory to your path.

       Example:

        PathAdd: /usr/local/rrdtool/bin/

   RRRRDDCCaacchheedd
       If you are running RRDTool 1.4 or later with rrrrddccaacchheedd, then you can
       configure MRTG to take advantage of this for updates, either by using
       the RRDCACHED_ADDRESS environment variable, or by setting the RRDCached
       keyword in the configuration file.  Note that, if both are set, the
       configuration file keyword will take precedence.

       Only UNIX domain sockets are fully supported prior to RRDTool v1.5, and
       you should note that using RRDCached mode will disable all Threshold
       checking normally done by MRTG.  Appropriate warning messages will be
       printed if necessary.

       Examples:

        RRDCached: unix:/var/tmp/rrdcached.sock

        RRDCached: localhost:42217

   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 configuration files happens only once on startup, and if the
       configuration file is modified.

       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.

       If the modification date on the configuration file changes during
       operation, then MRTG will re-read the configuration on the next polling
       cycle.  Note that sub-files which are included from the main
       configuration do not have their modification times monitored, only the
       top-level file is so checked.

   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 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 subroutine 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 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 "MyConversions.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 configuration
       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 subroutine
       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 monitor. 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.domain

           If your community contains a "@" or a " " these characters 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 normal 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 recommended that cfgmaker be used to generate
           configurations 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'

       noHC
           Not all routers that support SNMPv2 or SNMPv3 provide the ifHC*
           counters on every interface.  The noHC[] per-target keyword signals
           that the low-speed counters ifInOctets and ifOutOctets should be
           queried instead.  cfgmaker will automatically insert this tag if
           SNMPv2 or SNMPv3 is specified but the ifHC* counters are
           unavailable.

           Example:
             Target[myrouter]: #Bri0:router1:::::3
             SnmpOptions[myrouter]: username=>'user1'
             noHC[myrouter]: yes

       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 "Target" description. It flips the incoming and outgoing
           traffic rates.

           Example:

            Target[ezci]: -1:public@ezci-ether.domain

       Explicit OIDs
           You can also explicitly define which OID to query by using the
           following 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.

           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
           starting from 0 (!).

           Example:

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

             Target[myrouter]: WaLK3strangeOid.1&WaLK4strangeOid.2:public@myrouter

       SnmpGetNext
           A special case of an snmp object that is only reachable by
           'walking' occurs when a single snmpgetnext will return the correct
           value, but snmpwalk fails.  This may occur with snmp V2 or V3, as
           the snmpgetbulk method is used in these versions. You can get mrtg
           to use getnext instead of getbulk by prepending the OID with the
           string GGeeTTNNEEXXTT.

           Example:

             Target[myrouter]: GeTNEXTstrangeOid&GeTNEXTstrangeOid:public@myrouter

       Counted SNMP Walk
           In other situations, an snmpwalk is needed to count rows, but the
           actual data is uninteresting.  For example, counting the number of
           mac-addresses in a CAM table, or the number of simultaneous dialup
           sessions.  You can get MRTG to count the number of instances by
           prepending the OID with the string CCnnTTWWaaLLKK.  The following will
           retrieve the number of simultaneous VOIP calls on some routers:

           Example:

              Target[myrouter]: CnTWaLK1.3.6.1.4.1.9.10.55.1.1.1.1.3&CnTWaLK1.3.6.1.4.1.9.10.55.1.1.1.1.3: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
           target 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
           ----iiffrreeff==iipp.

           Example:

            Target[myrouter]: /1.2.3.4:public@wellfleet-fddi.domain
            Target[ezci]: -/1.2.3.4:public@ezci-ether.domain
            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.domain
            Target[ezci]: -\My-Interface2:public@ezci-ether.domain
            Target[myrouter]: ifInErrors\My-If2&ifOutErrors\My-If3: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 interfaces of your
           switches.

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

           Example:

            Target[myrouter]: #2/11:public@wellfleet-fddi.domain
            Target[ezci]: -#2/11:public@ezci-ether.domain
            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
           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 ----iiffrreeff==eetthh.

           Example:

            Target[myrouter]: !0a-0b-0c-0d:public@wellfleet-fddi.domain
            Target[ezci]: -!0-f-bb-05-71-22:public@ezci-ether.domain
            Target[myrouter]: 1.3.6.1.2.1.2.2.1.14!0a-00-10-23-44-51& *BREAK*
                       1.3.6.1.2.1.2.2.1.14!0a-00-10-23-44-51:public@myrouter
            Target[myrouter]: ifInErrors!0a-00-10-23-44-51& *BREAK*
                       ifOutErrors!0a-00-10-23-44-51:public@myrouter

           Join the lines at *BREAK* ...

       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 persistent 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.domain
            Target[ezci]: -%13:public@ezci-ether.domain
            Target[myrouter]: ifInErrors%13&ifOutErrors%14:public@myrouter

       Extended positioning of ifIndex
           There are OIDs that contain the interface index at some inner
           position within the OID. To use the above mentioned Interface by
           IP/Description/Name/Type methods in the target definition the
           keyword 'IndexPOS' can be used to indicate the position of ifIndex.
           If 'IndexPOS' is not used the ifIndex will be appended at the end
           of the OID.

           Example:

            Target[myrouter]: OID.IndexPOS.1/1.2.3.4&OID.IndexPOS.1/1.2.3.4:public@myrouter

           Replace OID by your numeric OID.

       Extended Host Name Syntax
           In all places where ``community@router'' is accepted, you can add
           additional parameters for the SNMP communication 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)

               The complete syntax of the port parameter is

                remote_port[!local_address[!local_port]]

               Some machines have additional security features that only allow
               SNMP queries to come from certain IP addresses. If the host
               doing the query has multiple interface, it may be necessary to
               specify the interface the query should come from.

               The port parameter allows the specification of the port of the
               machine being queried. In addition, the IP address (or
               hostname) and port of the machine doing the query may be
               specified.

               Examples:

                somehost
                somehost:161
                somehost:161!192.168.2.4!4000 use 192.168.2.4 and port 4000 as source
                somehost:!192.168.2.4 use 192.168.2.4 as source
                somehost:!!4000 use port 4000 as source

           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 counters 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
               conversion 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.domain: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_._d_o_m_a_i_n, 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.

           Example:

            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
               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 capacity.

           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 definition in the
           expression.  Target definitions themselves must not contain
           whitespace, 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
           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
           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
           collection and uses the collected data for each instance of a
           particular 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:public@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 monitored
       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 several interfaces
       you normally 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 _R_o_u_t_e_r_U_p_t_i_m_e keyword.

       If you want to use a special OID for querying the router uptime, use
       prepend the oid.

       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

        RouterUptime[kacisco.comp.edu]: hrSystemUptime.0:public@194.64.66.250

   RRoouutteerrNNaammee
       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
       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 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
       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 configuration 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',username=>'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 keyword 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 program to generate this
           hash, or use Net::SNMP::Security::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.

   CClloonneeddiirreeccttoorryy
       If the _D_i_r_e_c_t_o_r_y option is specified, the _C_l_o_n_e_d_i_r_e_c_t_o_r_y option will
       copy all the contents of _D_i_r_e_c_t_o_r_y to the _C_l_o_n_e_d_i_r_e_c_t_o_r_y.

       Example:

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

       Optionally the target name can be changed in the cloning process.

       Example:

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

       NOTE1: The clone directory must already exist; mrtg will not create it.

       NOTE2: The Clonedirectory option must also always be 'relative' or bad
       things will happen.

       NOTE3: This requires the File::Copy module

   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 YLegend 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 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 _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 intervals 5
           minute peak values. (Confused? Thought so!)

       gauge
           Treat the values gathered from target as 'current status'
           measurements 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
           variables as a counters and calculates the difference 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 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
           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 calculating 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 'Timezone' parameter. This is aequivalent to
           setting TimeStrPost[x]: RU

       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 consider a logarithmically
           scaled graph counterintuitive, however, and thus hard to interpret.

       expscale
           The eexxppssccaallee option causes rateup to display the data with the Y
           axis scaled exponentially.  Doing so emphasizes small changes at
           the top of the scale; this can be useful when graphing values that
           fluctuate by a small amount near the top of the scale, such as line
           voltage.

           eexxppssccaallee is essentially the inverse of llooggssccaallee.

       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 building 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 separated list
       of prefixed. Two consecutive commas or a comma at start or end of the
       line gives no prefix on this item.  If you do not want prefixes, just
       put two consecutive commas.  If you want to skip a magnitude select '-'
       as value.

       Example: velocity in nm/s (nanometers per second) displayed 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 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 _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 displayed 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 letter; 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 implementation 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 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
       configured for new rrds as they get created. Note that you must take
       the interval time into account.

       Example:

        RRDRowCount[myrouter]: 1600

   RRRRDDRRoowwCCoouunntt3300mm
       As per RRDRowCount, but for the RRA's -typically- used for 30 minute
       data.  Even so, you must still take the base interval into account.
       Leaving out this keyword will force the old default of 800 rows.

       Example:

        RRDRowCount30m[myrouter]: 800

   RRRRDDRRoowwCCoouunntt22hh
       As per RRDRowCount, but for the RRA's -typically- used for 2 hour data.
       Even so, you must still take the base interval into account.  Leaving
       out this keyword will force the old default of 800 rows.

       Example:

        RRDRowCount2h[myrouter]: 400

   RRRRDDRRoowwCCoouunntt11dd
       As per RRDRowCount, but for the RRA's -typically- used for 1 day data.
       Even so, you must still take the base interval into account.  Leaving
       out this keyword will force the old default of 800 rows.

       Example:

        RRDRowCount1d[myrouter]: 200

   RRRRDDHHWWRRRRAAss
       Normally the RRDs created by MRTG will just contain the information
       gathered directly from the respective target. With this option you can
       tap into rrdtools advanced aberrant behaviour detection module based on
       Holt-Winters forecasting. The RRDHWRRAs property specifies the Holt-
       Winters RRAs as described in the rrdcreate manual page.

       Note, this setting will only affect newly created RRDs (targets).

       Example:

        RRDHWRRAs[myrouter]: RRA:HWPREDICT:1440:0.1:0.0035:288

   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 boundary has been crossed.

       Example:

        ThreshDir: /var/mrtg/thresh

   TThhrreesshhHHyysstt ((GGLLOOBBAALL))
       If a threshold is broken, and you have a threshdir defined, then mrtg
       will send mail once the threshold becomes 'unborken' to avoid
       situations where broken and unbroken messages get sent in close
       succession, we only send an unbroken message once the curent value is
       0.1 (10%) away from the threshold.  using the ThreshHyst config
       variable you can customize this value.

       Example for 5%:

        ThreshHyst: 0.05

   TThhrreesshhMMaaiillSSeerrvveerr ((GGLLOOBBAALL))
       Adderss of an SMTP server which is going to accept mail about
       Thresholds being broken and unbroken.

   TThhrreesshhMMaaiillSSeennddeerr ((GGLLOOBBAALL))
       What is the sender address of the threshold mail.

       Example:

        ThreshMailSender: mrtg@example.com

   TThhrreesshhMMaaiillAAddddrreessss ((PPEERR TTAARRGGEETT))
       Email address for Threshold related Mails. This will only work if a
       mailserver has been configured.

       Example:

        ThreshMailAddress[_]: admin@example.com
        ThreshMailAddress[router]:

       This would bring threshold releaed mail to all but the target called
       'router'.

   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 and a mail will be sent to the
       ThreshMailAddress if specified.  If the value ends in '%' then the
       threshold is defined relative to MaxBytes.

   TThhrreesshhMMaaxxII ((PPEERR TTAARRGGEETT))
       Works the same as TheshMinI but it acts when the value is higher than
       ThreshMaxI.

   TThhrreesshhDDeesscc ((PPEERR TTAARRGGEETT))
       Its value will be assigned to the environment variable THRESH_DESC
       before any of the programs mentioned below are called. The programs 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 ThreshMaxI 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 currently OK
       (based on ThreshMinI and ThreshMaxI), but wasn't OK on the previous
       running -- based on the files found in ThreshDir. MRTG passes 3
       arguments: the $router variable the 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.

   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"

   HHWW FFaaiilluurree BBaasssseedd TThhrreesshhoolldd CChheecckkiinngg
       When using rrd based logging with HW RRAs defined. You can use the
       confidence bounds violations stored in the FAILURES RRA for threshold
       based alerts.

       There the all target specific threshold variables have a Hold-Winters
       counterpart:

        ThreshMailAddress -> HWThreshMailAddress
        ThreshMinI        -> HWThreshMinI
        ...

       The global variables for threshold checking are shared except for the

        ThreshHyst        -> HWThreshHyst

       And HWThreshDesc sets the HWTHRESH_DESC variable.

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-valued Keywords, but is not very useful
       for other Keywords. See the "default" target description below.

       The example will make mrtg use a common header and a common contact
       person in all the pages generated from targets defined later in this
       file.

       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.someplace.edu.2 in the
       above example will be 1250000, which was in effect where the target
       name myrouter.someplace.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 specification;
           http://www.pathname.com/fhs/

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

       ----ppiidd--ffiillee==ss
           Define the name and path of the pid file for mrtg running 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
            eval - print eval strings before evaluting them
            prof - add hires timing info the rrd calls

           Example:

            --debug="cfg,snpo"

EEXXIITT CCOODDEESS
       An exit code of 0 indicates that all targets were successful.
       Generally speaking, most codes greater than 0 indicate that there was
       an unrecoverable problem.  One exception to this is code 91, which
       indicates that at least one of the targets was successful.  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 <tobi@oetiker.ch> and many contributors



2.17.2                            2011-02-20                 MRTG-REFERENCE(1)
