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

N?NA?AM?ME?E

       mrtg-reference - MRTG 2.17.7 configuration reference

O?OV?VE?ER?RV?VI?IE?EW?W

       The runtime behaviour of MRTG is governed by a configuration file.

       Run-of-the-mill configuration files can be generated with c?cf?fg?gm?ma?ak?ke?er?r.

       (Check cfgmaker). But for more elaborate configurations some hand-

       tuning is required.

       This document describes all the configuration options understood by the

       mrtg software.

S?SY?YN?NT?TA?AX?X

       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

           I?In?nc?cl?lu?ud?de?e:?: _?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.

G?GL?LO?OB?BA?AL?L K?KE?EY?YW?WO?OR?RD?DS?S

   W?Wo?or?rk?kD?Di?ir?r

       WorkDir specifies where the logfiles and the webpages should be

       created.

       Example:

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

O?OP?PT?TI?IO?ON?NA?AL?L G?GL?LO?OB?BA?AL?L K?KE?EY?YW?WO?OR?RD?DS?S

   H?Ht?tm?ml?lD?Di?ir?r

       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/

   I?Im?ma?ag?ge?eD?Di?ir?r

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

       under the html directory.

       Example:

        Imagedir: /www/mrtg/images

   L?Lo?og?gD?Di?ir?r

       LogDir specifies the directory where the logs are stored.  This need

       not be under htmldir directive.

       Example:

        Logdir: /www/mrtg/logs

   F?Fo?or?rk?ks?s (?(U?UN?NI?IX?X o?on?nl?ly?y)?)

       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

   E?En?na?ab?bl?le?eI?IP?Pv?v6?6

       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

   E?En?na?ab?bl?le?eS?Sn?nm?mp?pV?V3?3

       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

   R?Re?ef?fr?re?es?sh?h

       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

   I?In?nt?te?er?rv?va?al?l

       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.

   M?Ma?ax?xA?Ag?ge?e

       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).

   W?Wr?ri?it?te?eE?Ex?xp?pi?ir?re?es?s

       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

   N?No?oM?Mi?ib?b2?2

       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

   S?Si?in?ng?gl?le?eR?Re?eq?qu?ue?es?st?t

       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

   S?Sn?nm?mp?pO?Op?pt?ti?io?on?ns?s

       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.

   I?Ic?co?on?nD?Di?ir?r

       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/

   L?Lo?oa?ad?dM?MI?IB?Bs?s

       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

   L?La?an?ng?gu?ua?ag?ge?e

       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

   L?Lo?og?gF?Fo?or?rm?ma?at?t

       Setting LogFormat to 'rrdtool' in your mrtg.cfg file enables rrdtool

       mode.  In rrdtool mode, mrtg relies on r?rr?rd?dt?to?oo?ol?l to do its logging. See

       mrtg-rrd.

       Example:

        LogFormat: rrdtool

   L?Li?ib?bA?Ad?dd?d

       If you are using rrdtool mode and your r?rr?rd?dt?to?oo?ol?l 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/

   P?Pa?at?th?hA?Ad?dd?d

       If the r?rr?rd?dt?to?oo?ol?l 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/

   R?RR?RD?DC?Ca?ac?ch?he?ed?d

       If you are running RRDTool 1.4 or later with r?rr?rd?dc?ca?ac?ch?he?ed?d, 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

   R?Ru?un?nA?As?sD?Da?ae?em?mo?on?n

       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 -?--?-u?us?se?er?r=?=_?u_?s_?e_?r_?__?n_?a_?m_?e

       and -?--?-g?gr?ro?ou?up?p=?=_?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.

   C?Co?on?nv?ve?er?rs?si?io?on?nC?Co?od?de?e

       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.

   S?Se?en?nd?dT?To?oG?Gr?ra?ap?ph?hi?it?te?e

       If you want to send a copy of the collected data into a Graphite

       database in addition to storing it in the RRDfile, you can provide your

       Graphite database name/ip and port number here.

       This requires the Net::Graphite perl module which is available from

       CPAN.

       Examples:

        # If your Graphite receiver is running on the same host as the MRTG daemon and using the default port

        SendToGraphite: 127.0.0.1,2003

        # If your Graphite receiver is running on 192.168.100.50 port 5000

        SendToGraphite: 192.168.100.50,5000

        # If your Graphite receiver is running on graphite.mydomain.com port 2003

        SendToGraphite: graphite.mydomain.com,2003

       Graphite's namespace has a number of restrictions on what characters

       are allowed. The SendToGraphite functionality makes an attempt to

       convert the MRTG target name and, if specified, the Legendi and Legendo

       values to Graphite namespace friendly values. Specifically, the

       following conversion rules apply:

       +?o   Underscores in the target_name are converted to periods which are

           Graphite namespace delimiters.

       +?o   Comma characters are not allowed so they are removed.

       +?o   The string "m2g" for MRTG to Graphite is prepended onto the

           Graphite namespace variable.

       Example MRTG target to Graphite namespace conversion:

        # Our MRTG target name from mrtg.cfg is as follows

        Target[switch_GigabitEthernet0_5]: \GigabitEthernet0/5:public1@switch:::::2

       After the conversion you will end up with these Graphite namespace

       values

        m2g.switch.gigabitethernet0.5.in

        m2g.switch.gigabitethernet0.5.out

       Next is a more complicated example because Legendi and Legendo are in

       use to denote min and max voltage values that pertain to some APC UPS

       SNMP OIDs

        # Target, Legendi, and Legendo are specified in mrtg.cfg as follows

        Target[apc_minmaxline]: 1.3.6.1.4.1.318.1.1.1.3.2.3.0&1.3.6.1.4.1.318.1.1.1.3.2.2.0:public@apc:

        LegendI[apc_minmaxline]: upsAdvInputMinLineVoltage

        LegendO[apc_minmaxline]: upsAdvInputMaxLineVoltage

       After the conversion you will end up with these Graphite namespace

       values

        m2g.apc.minmaxline.upsAdvInputMinLineVoltage

        m2g.apc.minmaxline.upsAdvInputMaxLineVoltage

       If you don't see the data showing up in Graphite, chances are there are

       invalid characters in the namespace. To debug this, use the

       DEBUG=qw(log) directive at the top of the MRTG script to find out what

       is happening with the MRTG to Graphite namespace conversion.

       DEBUG=qw(log) will generate some output similar to what appears below

        2016-10-13 06:08:39 -- --log: RRDs::update(/var/www/mrtg/switch/switch_gigabitethernet0_5.rrd, '1476356919:2738746035:2927936327')

        2016-10-13 06:08:39 -- --log: graphite->send(m2g.switch.gigabitethernet0.5.in,2738746035,1476356919)

        2016-10-13 06:08:39 -- --log: graphite->send(m2g.switch.gigabitethernet0.5.out,2927936327,1476356919)

        2016-10-13 06:09:25 -- --log: RRDs::update(/var/www/mrtg/apc/apc_minmaxline.rrd, '1476356965:122:123')

        2016-10-13 06:09:25 -- --log: graphite->send(m2g.apc.minmaxline.upsAdvInputMinLineVoltage,122,1476356965)

        2016-10-13 06:09:25 -- --log: graphite->send(m2g.apc.minmaxline.upsAdvInputMaxLineVoltage,123,1476356965)

       If the MRTG log output looks reasonable, then take a look at Graphite's

       carbon-cache logs.

P?PE?ER?R T?TA?AR?RG?GE?ET?T C?CO?ON?NF?FI?IG?GU?UR?RA?AT?TI?IO?ON?N

       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.

   T?Ta?ar?rg?ge?et?t

       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 W?Wa?aL?LK?K or if you want a particular entry from the

           table returned by the walk you can use W?Wa?aL?LK?K_?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 G?Ge?eT?TN?NE?EX?XT?T.

           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 C?Cn?nT?TW?Wa?aL?LK?K.  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

           -?--?-i?if?fr?re?ef?f=?=i?ip?p.

           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

           -?--?-i?if?fr?re?ef?f=?=d?de?es?sc?cr?r.

           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

           -?--?-i?if?fr?re?ef?f=?=n?na?am?me?e.

           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 -?--?-i?if?fr?re?ef?f=?=e?et?th?h.

           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

           -?--?-i?if?fr?re?ef?f=?=t?ty?yp?pe?e.

           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.