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

NAME
       mrtg-reference - MRTG 2.17.4 configuration reference

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

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

SYNTAX
       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

	   Include: file

	   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.

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

       Example:

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

OPTIONAL GLOBAL KEYWORDS
   HtmlDir
       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/

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

       Example:

	Imagedir: /www/mrtg/images

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

       Example:

	Logdir: /www/mrtg/logs

   Forks (UNIX only)
       With system that supports fork (UNIX for example), mrtg can fork itself into multiple
       instances while it is acquiring data via snmp.

       For situations with high latency or a great number of devices this will speed things up
       considerably. It will not make things faster, though, if you query a single switch sitting
       next door.

       As far as I know NT can not fork so this option is not available on NT.

       Example:

	Forks: 4

   EnableIPv6
       When set to yes, IPv6 support is enabled if the required libraries are present (see the
       mrtg-ipv6 manpage). When IPv6 is enabled, mrtg can talk to routers using SNMP over IPv6
       and targets may be specified by their numeric IPv6 addresses as well as by hostname or
       IPv4 address.

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

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

       IPv6 is disabled by default.

       Example:

	EnableIPv6: Yes

   EnableSnmpV3
       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

   Refresh
       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

   Interval
       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.

   MaxAge
       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).

   WriteExpires
       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

   NoMib2
       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

   SingleRequest
       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

   SnmpOptions
       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.

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

       Example:

	IconDir: /mrtgicons/

   LoadMIBs
       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

   Language
       Switch output format to the selected Language (Check the translate directory to see which
       languages are supported at the moment. In this directory you can also find instructions on
       how to create new translations).

       Currently the following laguages are supported:

       big5 brazilian bulgarian catalan chinese croatian czech danish dutch eucjp french galician
       gb gb2312 german greek hungarian icelandic indonesia iso2022jp italian korean lithuanian
       malay norwegian polish portuguese romanian russian russian1251 serbian slovak slovenian
       spanish swedish turkish ukrainian

       Example:

	Language: danish

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

       Example:

	LogFormat: rrdtool

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

       Example:

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

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

       Example:

	PathAdd: /usr/local/rrdtool/bin/

   RRDCached
       If you are running RRDTool 1.4 or later with rrdcached, 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

   RunAsDaemon
       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 --user=user_name and --group=group_name options on the
       mrtg commandline.

	mrtg --user=mrtg_user --group=mrtg_group mrtg.cfg

       Also note that in daemon mode restarting the process is required in order to activate
       changes in the config file.

       Under UNIX, the Daemon switch causes mrtg to fork into background after checking its
       config file. On Windows NT the MRTG process will detach from the console, but because the
       NT/2000 shell waits for its children you have to use this special start sequence when you
       launch the 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.

   ConversionCode
       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.

PER TARGET CONFIGURATION
       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.

   Target
       With the Target keyword you tell mrtg what it should monitor. The Target 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 WaLK or if you want a
	   particular entry from the table returned by the walk you can use WaLKx 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 GeTNEXT.

	   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 CnTWaLK.  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 --ifref=ip.

	   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 --ifref=descr.

	   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 --ifref=name.

	   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 --ifref=eth.

	   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 --ifref=type.

	   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 ifIndex 1
	   on ezci-ether.domain, 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 Options 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.

   MaxBytes
       The maximum value either of the two variables monitored are allowed to reach. For
       monitoring router traffic this is normally the bytes per second this interface port can
       carry.

       If a number higher than MaxBytes is returned, it is ignored.  Also read the section on
       AbsMax for further info.  The MaxBytes value is also used in calculating the Y range for
       unscaled graphs (see the section on Unscaled).

       Since most links are rated in bits per second, you need to divide their maximum bandwidth
       (in bits) by eight (8) in order to get bytes per second.  This is very important to make
       your unscaled graphs display realistic information. T1 = 193000, 56K = 7000, 10 MB
       Ethernet = 1250000, 100 MB Ethernet = 12500000. The MaxBytes value will be used by mrtg to
       decide whether it got a valid response from the router.

       If you need two different MaxBytes values for the two monitored variables, you can use
       MaxBytes1 and MaxBytes2 instead of MaxBytes.

       Example:

	MaxBytes[myrouter]: 1250000

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

       Example:

	Title[myrouter]: Traffic Analysis for Our Nice Company

OPTIONAL PER TARGET KEYWORDS
   PageTop
       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.

   RouterUptime
       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 RouterUptime 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

   RouterName
       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

   MaxBytes1
       Same as MaxBytes, for variable 1.

   MaxBytes2
       Same as MaxBytes, for variable 2.

   IPv4Only
       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

   SnmpOptions (V3)
       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.

       Security Modes

       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'

       snmp options

       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.

   PageFoot
       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

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

       Example:

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

   BodyTag
       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">

   AbsMax
       If you are monitoring a link which can handle more traffic than the MaxBytes value. Eg, a
       line which uses compression or some frame relay link, you can use the AbsMax keyword to
       give the absolute maximum value ever to be reached. We need to know this in order to sort
       out unrealistic values returned by the routers. If you do not set AbsMax, rateup will
       ignore values higher than MaxBytes.

       Example:

	AbsMax[myrouter]: 2500000

   Unscaled
       By default each graph is scaled vertically to make the actual data visible even when it is
       much lower than MaxBytes.  With the Unscaled variable you can suppress this.  It's
       argument is a string, containing one letter for each graph you don't want to be scaled:
       d=day w=week m=month y=year.  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

   WithPeak
       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

   Suppress
       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

   Extension
       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

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

       If the Directory option is specified, the files are instead put into a directory under
       WorkDir or Log-, Image- and HtmlDir).  (For example the Directory option below would cause
       all the files for a target 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.

   Clonedirectory
       If the Directory option is specified, the Clonedirectory option will copy all the contents
       of Directory to the Clonedirectory.

       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

   XSize and YSize
       By default mrtgs graphs are 100 by 400 pixels wide (plus some more for the labels. In the
       example we get almost square graphs ...

       Note: XSize must be between 20 and 600; YSize must be larger than 20

       Example:

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

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

       Example:

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

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

       Example:

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

   YTics and YTicsFactor
       If you want to show more than 4 lines per graph, use YTics.  If you want to scale the
       value used for the YLegend of these tics, use 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

   Factor
       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

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

       Example:

	Step[myrouter]: 60

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

       Example:

	PNGTitle[myrouter]: WAN Link UK-US

   Options
       The Options 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 Colours 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 logscale 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.

	   logscale 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 expscale 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.

	   expscale is essentially the inverse of logscale.

       secondmean
	   The secondmean 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 secondmean 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 logscale and secondmean in the options, the secondmean takes
	   precedence.

       Example:

	Options[myrouter]: growright, bits

   kilo
       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

   kMG
       Change the default multiplier prefixes (,k,M,G,T,P). In the tag ShortLegend 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

   Colours
       The Colours tag allows you to override the default colour scheme.  Note: All 4 of the
       required colours must be specified here. The colour name ('Colourx' below) is the legend
       name displayed, while the RGB value is the real colour used for the display, both on the
       graph and in the html doc.

       Format is: Col1#RRGGBB,Col2#RRGGBB,Col3#RRGGBB,Col4#RRGGBB

       Important: If you use the dorelpercent options tag a fifth colour name colour value pair
       is required: Col1#RRGGBB,Col2#RRGGBB,Col3#RRGGBB,Col4#RRGGBB,Col5#RRGGBB

       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

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

       Example:

	Background[myrouter]: #a0a0a0a

   YLegend, ShortLegend, Legend[1234]
       The following keywords allow you to override the text displayed for the various legends of
       the graph and in the HTML document:

       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 LegendI or LegendO are set to an empty string with

	LegendO[myrouter]:

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

   Timezone
       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.

   Weekformat
       By default, mrtg (actually rateup) uses the strftime(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 strftime(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

   RRDRowCount
       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

   RRDRowCount30m
       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

   RRDRowCount2h
       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

   RRDRowCount1d
       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

   RRDHWRRAs
       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

   TimeStrPos
       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

   TimeStrFmt
       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 strftime()
       function - see strftime(3) documentation for conversion specifiers available on your
       system.	Default format: %Y-%m-%d %H:%M

       Example:

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

THRESHOLD CHECKING
       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:

   ThreshDir (GLOBAL)
       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

   ThreshHyst (GLOBAL)
       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

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

   ThreshMailSender (GLOBAL)
       What is the sender address of the threshold mail.

       Example:

	ThreshMailSender: mrtg@example.com

   ThreshMailAddress (PER TARGET)
       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'.

   ThreshMinI  (PER TARGET)
       This is the minimum acceptable value for the Input (first) parameter.  If the parameter
       falls below this value, the program specified in ThreshProgI will be run and a mail will
       be sent to the ThreshMailAddress if specified.  If the value ends in '%' then the
       threshold is defined relative to MaxBytes.

   ThreshMaxI (PER TARGET)
       Works the same as TheshMinI but it acts when the value is higher than ThreshMaxI.

   ThreshDesc (PER TARGET)
       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.

   ThreshProgI	(PER TARGET)
       This defines a program to be run if ThreshMinI or ThreshMaxI is broken.	MRTG passes 3
       arguments: the $router variable, the threshold value broken, and the current parameter
       value.

   ThreshProgOKI  (PER TARGET)
       This defines a program to be run if the parameter is currently OK (based on ThreshMinI and
       ThreshMaxI), but wasn't OK on the previous running -- based on the files found in
       ThreshDir. MRTG passes 3 arguments: the $router variable the unbroken threshold value, and
       the current parameter value.

   ThreshMinO, ThreshMaxO, ThreshProgO, and ThreshProgOKO
       These work the same as their *I counterparts, except on the Output (second) parameter.

   SetEnv
       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"

   HW Failure Bassed Threshold Checking
       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.

PER TARGET DEFAULT VALUES
   Pre- and Postfix
       To save yourself some typing you can define a target called '^'. The text of every Keyword
       you define for this target will be PREPENDED to the corresponding Keyword of all the
       targets defined below this line. The same goes for a Target called '$' but its text will
       be APPENDED.

       Note that a space is inserted between the prepended text and the 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[$]:

   NoSpaceChar
       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 NoSpaceChar 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

   Default Values
       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 MaxBytes 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.

COMMAND LINE OPTIONS
       --user username	and --group groupname
	   Run as the given user and/or group. (Unix Only)

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

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

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

	   NOTE: Note, there is no Message DLL for mrtg 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.

       --daemon
	   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)

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

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

       --pid-file=s
	   Define the name and path of the pid file for mrtg running as a daemon

       --debug=s
	   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"

EXIT CODES
       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

EXAMPLES
   Minimal mrtg.cfg
	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>

   Cfg for several Routers.
	WorkDir: /usr/tardis/pub/www/stats/mrtg
	Title[^]: Traffic Analysis for
	PageTop[^]: <H1>Stats for
	PageTop[$]: Contact The Chief if you notice anybody<HR>
	MaxBytes[_]: 8000
	Options[_]: growright

	Title[isdn]: our ISDN Line
	PageTop[isdn]: our ISDN Line</H1>
	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

AUTHOR
       Tobias Oetiker <tobi@oetiker.ch> and many contributors

2.17.4					    2012-01-12				MRTG-REFERENCE(1)
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