cfgmaker - Creates mrtg.cfg files (for mrtg-2.9.17)
cfgmaker [options] [community@]router [[options] [community@]router ...]
--ifref=nr interface references by Interface Number (default) --ifref=ip ... by Ip Address --ifref=eth ... by Ethernet Number --ifref=descr ... by Interface Description --ifref=name ... by Interface Name --ifref=type ... by Interface Type
--ifdesc=nr interface description uses Interface Number (default) --ifdesc=ip ... uses Ip Address --ifdesc=eth ... uses Ethernet Number --ifdesc=descr ... uses Interface Description --ifdesc=name ... uses Interface Name --ifdesc=alias ... uses Interface Alias --ifdesc=type ... uses Interface Type
--if-filter=f Test every interface against filter f to decide wether
or not to include that interface into the collection.
Currently f is being evaluated as a Perl expression
and it's truth value is used to reject or accept the
interface.
(Experimental, under development, might change)
--if-template=templatefile
Replace the normal target entries for the interfaces
with an entry as specified by the contents in the file
templatefile. The file is supposed to contain Perl
code to be executed to generate the lines for the
target in the configuration file.
(Experimental, under development, might change)
--host-template=templatefile
In addition to creating targets for a host's interfaces
do also create targets for the host itself as specified
by the contents in the file templatefile. The file is
supposed to contain Perl code to be executed to generate
the lines for the host related targets (such as CPU,
ping response time measurements etc.) in the config-
uration file.
(Experimental, under development, might change)
--global "x: a" add global config entries
--no-down do not look at admin or opr status of interfaces
--show-op-down show interfaces which are operatively down
--descint describe interface instead of just 'Traffic Analysis for'
--subdirs=format give each router its own subdirectory, naming each per
"format", in which HOSTNAME and SNMPNAME will be
replaced by the values of those items -- for instance,
--subdirs=HOSTNAME or --subdirs="HOSTNAME (SNMPNAME)"
--noreversedns do not reverse lookup ip numbers
--community=cmty Set the default community string to "cmty" instead of
"public".
--snmp-options=:[<port>][:[<tmout>][:[<retr>][:[<backoff>][:<ver>]]]]
Specify default SNMP options to be appended to all
routers following. Individual fields can be empty.
Routers following might override some or all of the
options given to --snmp-options.
--dns-domain=domain
Specifies a domain to append to the name of all
routers following.
--nointerfaces Don't do generate any configuration lines for interfaces,
skip the step of gathering interface information and
don't run any interface template code.
--interfaces Generate configuration lines for interfaces (this is the
default). The main purpose of this option is to negate
an --nointerfaces appearing earlier on the command line.
--help brief help message --man full documentation --version print the version of cfgmaker
--output=file output filename default is STDOUT
Cfgmaker creates MRTG configuration files based on information pulled from a router or another SNMP manageable device.
[community@]router
Community is the community name of the device you want to create a configuration for. If not specified, it defaults to 'public'; you might want to try this first if you do not know the community name of a device. If you are using the wrong comunity name you will get no response from the device.
Router is the DNS name or the IP number of an SNMP-managable device. Following the name you can specify 6 further options separated by colons. The full syntax looks like this:
router[:[prt][:[tmout][:[retr][:[backoff][:vers]]]]]
Of special interest may be the last parameter, vers. If you set this to '2' then your device will be queried with SNMP version 2 requests. This allows to poll the 64 bit traffic counters in the device and will thus work much better with fast interfaces (no more counter overrun). Note that the order in which the routers are specified on the command line do matter as the same order is used when the configuration file is generated. The first specified router has it's configuration lines genrated first, followed by the lines belonging to the next router and so on.
Except for the --output and --global options, all options affect only the routers following them on the command line. If an option specified earlier on the command line reappears later on the command line with another value, the new value overrides the old value as far as remaining routers are concerned. This way options might be tailored for groups of routers or for individual routers.
See --output and --global for how their behaviour is affected by where or how many times they appear on the command line.
See the Examples below on how to set an option differently for multiple routers.
To work around this sad problem MRTG can identify interfaces by 4 other properties. None of these works for all interfaces, but you should be able to find one which does fine for you. Note that especially ethernet addrsses can be problematic as some routers have the same ethernet address on most of their interface cards.
Select ip to identify the interface by its IP number. Use eth to use the ethernet address for identification. Use descr to use the Interface description. Or use name to use the Interface name.
If your chosen method does not allow unique interface identification on the device you are querying, cfgmaker will tell you about it.
Title[] property for the target as well as the text header
in the HTML code defined in the target's PageTop[]. Default is to use
nr which is just the interface number which isn't always useful
to the viewer of the graphs.
There are 6 other properties which could be used. Use ip if you want
to use the interface's IP-address. Use eth if you want to use the
interface's ethernet address. If you want a better description, you can
use either descr, name or alias. Exactly what each of these do
varies between different equipment so you might need to experiment. For
instance, for a serial interface on a Cisco router running IOS using name
might result in "S0" being the interface description , descr might result
in "Serial0" and alias might result in "Link to HQ" (provided that is
what is used as the interface's description in the router's configuration).
Finally, if you want to describe the interface by it's Btype
(i.e "ethernetCSMA", "propPointtoPoint" etc) you can use type. This is
roughly equivalent to the --descint option above.
Use this if you want to have better control over what interfaces gets included into the configuration. The filter-expression is evaluated as a piece of Perl code and is expected to return a truth value. If true, include the interface and if false, exclude the interface.
For a further discussion on how these filters work, see the section DETAILS ON FILTERS below.
Use this if you want to control what the line for each target should look like in the configuration file. The contents of the file template-file will be evaluated as a Perl program which generates the lines using certain variables for input and output.
For a further discussion on how these templates work, see the section DETAILS ON TEMPLATES below.
Use this if you want to have some extra targets related to the host itself such as CPU utilization, ping response time to the host, number of busy modems etc. The contents of the file template-file will be evaluated once per host as a Perl program which generates the lines using certain variables for input and output.
For a further discussion on how these templates work, see the section DETAILS ON TEMPLATES below.
router[:[port][:[timeout][:[retries][:[backoff][:version]]]]]
--global "workdir: /home/mrtg"
If you want some default Options you might want to put
--global "options[_]: growright,bits"
Specifying --global after the last router on the command line will create a line in the configuration file which will appear after all the routers.
cfgmaker --subdirs=HOSTNAME__SNMPNAME [email protected]
would result in the generation of lines looking something like:
Directory[10.10.0.18_1]: 10.10.0.18__fp2200-bothrip-1.3
STDOUT. --output is expected to appear only once on the
command line. If used multiple times, the file specified by the last
--output will be used.
This makes cfgmaker skip all steps related to interfaces which means it will not do any polling of the router to retrieve interface information which speeds up the execution of cfgmaker and it will neither run any interface templates.
The main usage of this option is to negate an --nointerfaces appearing earlier on the command line.
The purpose of the filters is to decide which interfaces to accept and which interfaces to reject. This decision is done for each interface by evaluating the filter expression as a piece of Perl code and investigating the result of the evaluation. If true, accept the interface otherwise reject it.
When working with filters, remember that Perl has it's own idea of what truth and false is. The empty string ``'' and the string ``0'' are false, all other strings are true. This further imples that any integer value of 0 is false as well as any undef value. It also implies that all references are considered true.
As the filter is evaluated as a Perl expression, several useful constructs in Perl are worth mentioning:
Expressions might be grouped by using parentheses ``()''. Expressions might be combined using boolean operators such as the following:
(For more details on this I recommend a book on Perl)
To facilitate, there are a number of predefined values available to use in the filter. Note that these variables are also available when templates interfaces are evaluated (but not host templates).
Caveat: All these variables' names begin with a dollar sign ($), which is a syntactic requirement for scalar variables in Perl. The danger here is that the dollar sign in many shells is an active character (often used for shell variables exactly as in Perl variables) so it is important to ensure that the Perl expression isn't evaluated by the command line shell as shell code before being passed to cfgmaker as command line arguments. In shells like Bourne shell, ksh shell or bash shell, placing the entire expression within single qoutes will avoid such accidental evaluation:
'--if-filter=($default_iftype && $if_admin)'
Here's a list of some of the most common interface types by number:
6 ethernetCsmacd 7 iso88023Csmacd 9 iso88025TokenRing 15 fddi 19 E1 20 basicISDN 21 primaryISDN 22 propPointToPointSerial 23 ppp 24 softwareLoopback 30 ds3 32 frame-relay 33 rs232 37 atm 39 sonet 44 frameRelayService 46 hssi 49 aal5 53 propVirtual 62 Fast Ethernet (100BaseT) 63 ISDN & X.25 69 Full Duplex Fast Ethernet (100BaseFX) 94 Asymetric Digital Subscriber Loop (ADSL) 117 Gigabit Ethernet 134 ATM Sub Interface
A number of variables are also predefined to easily decide if an interface belong to a certain cathegory or not. Below is all those variables listed together with which if_type numbers each variable will be true for. Note that some variables refer to other variables as well.
Besides of that, all the variables available in cfgmaker is at the scripts disposal even if the use of such features is discouraged. More ``shortcuts'' in the form of variables and functions will be made avaiable in the future instead.
The following filter will not affect which interfaces get's included or excluded, it will make cfgmaker behave as normally.
'--if-filter=$default'
The following filter will make cfgmaker exclude PPP (23) interfaces:
'--if-filter=$default && $if_type!=23'
The following filter will make cfgmaker behave as usual except that it will consider the operational state of an interface irrelevant but still reject all interfaces which are administratively down.
'--if-filter=$if_admin && $default_iftype'
The contents of the template files are evaluated as a Perl program. A number or Perl variables are available for the program to read and others are used to be written to.
As quite a few of the predefined variables has values which are are supposed to be used in HTML code some of them have an ``HTML-escaped'' variant, e.g $html_syslocation is the HTML escaped variant of $syslocation. The HTML escaping means that the chars ``<'', ``>'' and ``&'' are replaced by ``<'', ``>'' and ``&'' and that newlines embedded in the string are prepended with ``<BR>'' and appended with a space character (if a newline is last in the string it is not touched).
These are the variables available to store the configuration lines in. Some of them are initialized prior to the evaluation of the template but such content normally is comments for inclusion in the final configuration file so those variables might be reset to the empty string in the template code to eliminate the comments. The other way around is also possible, the contents of these variables might be extended with further information for various reasons such as debugging etc.
Once the template has been evaluated, the following happens: if the template is a interface template and the actual interface for some reason is rejected and thus needs to be commented out, all the lines in the variable $target_lines are turned into comments by adding a hash mark (``#'') at their beginning. Then all the variables $head_lines, $problem_lines , $target_lines and $separator_lines are concatenated together to form the lines to add to the configuration file.
It is possible to test against $problem_lines to find out if an interface will be included or rejected but this is not recommended. Test against $if_ok instead.
All the variables below are available for interface templates to use. For host templates, only those listed under Host and System Variables are available.
For interface templates the variables listed under Predefined Filter Variables are also available.
By default cfgmaker uses the following directives for each target it generates: Target[], SetEnv[], MaxBytes[], Title[], PageTop[] and if there is any directory specified also the Directory[] directive.
To facilitate the creation of templates which generates target configs which are similar to the default one, each of the above mentioned directive lines have a corresponding variable containing the line as cfgmaker would have output it by default.
Note that none of these have a HTML escaped variant, text in them is HTML escaped where needed. Also note that they do not have any newline at the end.
It might seem confusing with both Name, Description and Alias in this context and to some extent it is. Name and Description are usually supported on most equipment but how they are used varies, both between manufacturers as well as between different cathegories of equipment from the same manufacturer. The Alias is at least supported by Cisco IOS, and that variable contains whatever is used in the IOS statement called ``description'' for the interface (not to be confused with the SNMP variables for Description).
For better control from the command line consider $if_title_desc which contents are controlled by the --if-descr command line option.
As $if_title depends on $if_title_desc, it is possible to indirectly control $if_title by using the command line option --if-descr.
(HTML escaped variant: $html_if_title)
$if_title_desc is controlled by the command line option --if-descr which indirectly controls the contents of $if_title
(HTML escaped variant: $html_if_title_desc)
The following functions exists to facilitate the writing of host and interface templates.
This template file generates exactly the same configuration code per interface as cfgmaker does by default, with the exception that it eliminates all lines (comments as well as config code) for an interface if the interface happens to be rejected.
if(not $problem_lines)
{
$target_lines .= <<ECHO;
Target[$target_name]: $if_ref:$router_connect SetEnv[$target_name]: MRTG_INT_IP="$if_ip" MRTG_INT_DESCR="$if_snmp_descr" ECHO
if ($directory_name) {
$target_lines .= "Directory[$target_name]: $directory_name\n";
}
$target_lines .= <<ECHO;
MaxBytes[$target_name]: $if_speed
Title[$target_name]: $html_desc_prefix$html_if_title_desc -- $sysname
PageTop[$target_name]: <H1>$html_desc_prefix$html_if_title_desc -- $sysname</H1>
<TABLE>
<TR><TD>System:</TD> <TD>$sysname in $html_syslocation</TD></TR>
<TR><TD>Maintainer:</TD> <TD>$html_syscontact</TD></TR>
<TR><TD>Description:</TD><TD>$html_if_description</TD></TR>
<TR><TD>ifType:</TD> <TD>$html_if_type_desc ($if_type_num)</TD></TR>
<TR><TD>ifName:</TD> <TD>$html_if_snmp_name</TD></TR>
ECHO
$target_lines .= <<ECHO if defined $if_port_name;
<TR><TD>Port Name:</TD> <TD>$if_port_name</TD></TR>
ECHO
$target_lines .= <<ECHO;
<TR><TD>Max Speed:</TD> <TD>$if_speed_str</TD></TR>
ECHO
$target_lines .= <<ECHO if $if_ip;
<TR><TD>Ip:</TD> <TD>$if_ip ($if_dns_name)</TD></TR>
ECHO
$target_lines .= <<ECHO;
</TABLE>
ECHO
} else {
$head_lines="";
$problem_lines="";
$target_lines="";
$separator_lines="";
}
Example 1 was partly intended to demonstrate how to customize the generation of interface targets but also to provide a hint of how the variables are used in the ``default'' template which one could consider that cfgmaker normally uses.
If you're only intrested in the easiest way of entirely eliminating those reject interfaces, the template below would do the job as well by using $default_target_lines.
if($if_ok) {
$target_lines = $default_target_lines;
} else {
$head_lines="";
$problem_lines="";
$target_lines="";
$separator_lines="";
}
=head3 Template Example 3: Creating CPU Targets for Hosts
Below is an example of a host template.
$head_lines .= <<ECHO; #--------------------------------------------------------------------- ECHO
my $target_name = $router_name . ".cpu";
$target_lines .= <<ECHO;
YLegend[$target_name]: Percentage CPU load
ShortLegend[$target_name]: %
Legend1[$target_name]: CPU load in %
Legend2[$target_name]:
Legend3[$target_name]: Max Observed CPU load
Legend4[$target_name]:
LegendI[$target_name]: CPU Load:
LegendO[$target_name]:
WithPeak[$target_name]: ywm
MaxBytes[$target_name]: 100
Options[$target_name]: growright, gauge, nopercent
Title[$target_name]: $router_name CPU load
Target[$target_name]: 1.3.6.1.4.1.9.2.1.58.0&1.3.6.1.4.1.9.2.1.58.0:$router_connect
PageTop[$target_name]: <H1>$router_name CPU load</H1>
<TABLE>
<TR><TD>System:</TD><TD>$router_name in $html_syslocation</TD></TR>
<TR><TD>Maintainer:</TD><TD>$html_syscontact</TD></TR>
<TR><TD VALIGN="top">Description:</TD><TD>$html_sysdescr</TD></TR>
<TR><TD>Resource:</TD><TD>CPU.</TD></TR>
</TABLE>
ECHO
The first example creates a config file for router.place.xyz: the router has the community name public. Interfaces get identified by their IP number. Two global options get added to the config file. The config file gets redirected to mrtg.conf. The '\' signs at the end of the line mean that this command should be written on a single line.
cfgmaker --global "WorkDir: /home/tobi" \
--global "Options[_]: growright,bits" \
--ifref=ip \
[email protected] > mrtg.cfg
The next example creates a config file for four devices: router1.place.xyz, router2.place.xyz, switch1.place.xyz and switch2.place.xyz all with the community public.
The two routers will have --ifref set to descr whilst the two switches will use --ifref set to name. Further the routers will use --ifdesc set to alias and switch1.place.xyz will use --ifdesc set to descr whilst switch2.place.xyz use name instead.
Finally, there will be two Options lines inserted in the configuration: One will be in the beginning, whilst the other will be inserted after the lines related to the two routers but before those lines related to the switches.
cfgmaker --global "WorkDir: /home/tobi" \
--global "Options[_]: growright,bits" \
--ifref=descr \
--ifdesc=alias \
[email protected] \
[email protected] \
--global "Options[_]: growright" \
--ifref=name \
--ifdesc=descr \
[email protected] \
--ifdesc=name \
[email protected] > mrtg.cfg
The next example demonstrates how to use the --community, --snmp-options and --dns-domain to make the command line simpler. All the equipment will use the community hidden, except for the ppp-server which use community access. All equipment uses these SNMP options: 1s timeout, 1 retry and SNMP version 2 (backoff and port is unspecified which means they use the default values). The exception again is the ppp-server which uses SNMP version 1. Finally, all the equipment is part of the domain place.xyz, except for the ppp-server which is part of the domain remote.place.xyz. Note that the latter is achieved simply by specifying the name of the ppp-server to be ppp-server.remote .
cfgmaker --global "WorkDir: /home/tobi" \
--global "Options[_]: growright,bits" \
--dns-domain=place.xyz \
--community=hidden \
--snmp-options=::1:1::2 \
router1 \
router2 \
router3 \
router4 \
router5 \
switch1 \
switch2 \
switch3 \
switch4 \
switch5 \
switch6 \
switch7 \
[email protected]:::::1 > mrtg.cfg
Tobias Oetiker <[email protected]> and Jakob Ilves <[email protected]>
GNU General Public License
Cfgmaker is Copyright 2000 by Tobias Oetiker <[email protected]>