From Linux Man Pages
cfgmaker - Creates mrtg.cfg files (for mrtg-2.14.7)
cfgmaker [options] [community@]router [[options] [community@]router ...]
OPTIONS
--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=catname ... uses CatOS 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
--zero-speed=spd use this speed in bits-per-second as the interface
speed for all interfaces that return a speed of 0
via ifSpeed/ifHighSpeed. 100Mbps = 100000000
--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".
--enable-ipv6 Enable IPv6 support, if the required libraries are
present. Numeric IPv6 addresses must be enclosed
in square brackets, e.g. public@[2001:760:4::1]:161
--use-16bit Use 16bit SNMP request IDs to query all routers.
--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
DESCRIPTION
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 community 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 fur-
ther 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 speci-
fied 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.
Note that the first line of the generated cfg file will contain all the commandline options you used for generat-
ing it. This is to allow for the easy 'regeneration' in case you want to add newhosts or make some other global
change.
Configuration
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 tai-
lored 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 com-
mand line.
See the Examples below on how to set an option differently for multiple routers.
--help
Print a brief help message and exit.
--man
Prints the manual page and exits.
--version
Print the version of cfgmaker. This should match the version of MRTG for which config files are being cre-
ated.
--ifref nr|ip|eth|descr|name
Select the interface identification method. Default is nr which identifies the router interfaces by their
number. Unfortunately the interface numbering scheme in an SNMP tree can change. Some routers change their
numbering when new interfaces are added, others change thier numbering every full moon just for fun.
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.
--ifdesc nr|ip|eth|descr|name|type|alias
Select what to use as the description of the interface. The description appears in the "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.
--if-filter 'filter-expression'
First of all, this is under some developement and is experimental.
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.
--if-template template-file
First of all, this is under some development and is experimental.
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 Temaplates" below.
--host-template template-file
First of all, this is under some development and is experimental.
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 evalu-
ated 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.
--community community-string
Use this to set the community for the routers following on the command line to community-string. Individual
routers might overrride this community string by using the syntax community@router.
--enable-ipv6
This option enables IPv6 support. It requires the appropriate perl modules; if they are not found then IPv6
is disabled (see the ipv6 documentation).
cfgmaker will use IPv6 or IPv4 depending on the target. If the target is a numeric address, the protocol
depends on the type of address. If the target is a hostname, cfgmaker will try to resolve the name first to
an IPv6 address then to an IPv4 address.
IPv6 numeric addresses must be specified between square braces.
For example:
cfgmaker --enable-ipv6 [2001:760:4::1]:165:::2
If the target has both an IPv6 address and an IPv4 address with the same hostname, cfgmaker first queries the
target using IPv6 and falls back to IPv4 if it fails. This is useful for targets which don't support SNMP
over IPv6.
--use-16bit
This option forces the use of 16bit SNMP request IDs. Some broken SNMP agents do not accept 32bit request
IDs. Try to avoid this option as much as possible, complain to your agent vendor instead.
--snmp-options :[port][:[timeout][:[retries][:[backoff][:version]]]]
Use this to set the default SNMP options for all routers following on the command line. Individual values
might be omitted as well as trailing colons. Note that routers might override individual (or all) values
specified by --snmp-options by using the syntax
router[:[port][:[timeout][:[retries][:[backoff][:version]]]]]
--global "bla: abc"
Use this to add global options to the generated config file. You can call --global several times to add mul-
tiple options. The line will appear in the configuration just before the config for the next router appear-
ing on the command line.
--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.
--noreversedns
Do not try to reverse lookup IP numbers ... a must for DNS free environments.
--no-down
Normally cfgmaker will not include interfaces which are marked anything but administratively and opera-
tionally UP. With this switch you get them all.
--show-op-down
Include interfaces which are operatively down.
--zero-speed speed
Assign this speed in bits-per-second to all interfaces which return 0 for ifSpeed and ifHighSpeed. Some
switches, notably Foundry equipment, return a speed of zero for some interfaces. For example, to have all
interfaces reporting zero set to 100Mbps, use --zero-speed=100000000.
--subdirs format
Give each router its own subdirectory for the HTML and graphics (or .rrd) files. The directory name is the
given format string with a couple of pattern replacements. The string "HOSTNAME" will be replaced by the
hostname of the router (however you specified it on the cfgmaker commandline -- it may be an actual hostname
or just an IP address), and "SNMPNAME" will be replaced with the device's idea of its own name (the same name
that appears on the right side of the "Title" lines). For instance, a call like:
cfgmaker --subdirs=HOSTNAME__SNMPNAME public@10.10.0.18
would result in the generation of lines looking something like:
Directory[10.10.0.18_1]: 10.10.0.18__fp2200-bothrip-1.3
--output file
Write the output from cfgmaker into the file file. The default is to use "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.
--nointerfaces
Don't generate configuration lines for interfaces.
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.
--interfaces
This makes cfgmaker generate configuration lines for interfaces (the default behaviour).
The main usage of this option is to negate an --nointerfaces appearing earlier on the command line.
SNMP V3 Options
Cfgmaker supports SNMP V3. There are optional parameters affecting SNMP operation.
SNMPv3 Arguments
A SNMP context is a collection of management information accessible by a SNMP entity. An item of management
information may exist in more than one context and a SNMP entity potentially has access to many contexts. The
combination of a contextEngineID and a contextName unambiguously identifies a context within an administrative
domain. In a SNMPv3 message, the contextEngineID and contextName are included as part of the scopedPDU. All
methods that generate a SNMP message optionally take a --contextengineid and --contextname argument to configure
these fields.
Context Engine ID
The --contextengineid argument expects a hexadecimal string representing the desired contextEngineID. The
string must be 10 to 64 characters (5 to 32 octets) long and can be prefixed with an optional "0x". Once the
--contextengineid is specified it stays with the object until it is changed again or reset to default by
passing in the undefined value. By default, the contextEngineID is set to match the authoritativeEngineID of
the authoritative SNMP engine.
Context Name
The contextName is passed as a string which must be 0 to 32 octets in length using the --contextname argu-
ment. The contextName stays with the object until it is changed. The contextName defaults to an empty
string which represents the "default" context.
User-based Security Model Arguments
The User-based Security Model (USM) used by SNMPv3 requires that a securityName be specified using the --username
argument. The creation of a Net::SNMP object with the version set to SNMPv3 will fail if the --username argument
is not present. The --username argument expects a string 1 to 32 octets in length.
Different levels of security are allowed by the User-based Security Model which address authentication and
privacy concerns. A SNMPv3 target will derive the security level (securityLevel) based on which of the following
arguments are specified.
By default a securityLevel of 'noAuthNoPriv' is assumed. If the --authkey or --authpassword arguments are speci-
fied, the securityLevel becomes 'authNoPriv'. The --authpassword argument expects a string which is at least 1
octet in length. Optionally, the --authkey argument can be used so that a plain text password does not have to
be specified in a script. The --authkey argument expects a hexadecimal string produced by localizing the pass-
word with the authoritativeEngineID for the specific destination device. The "snmpkey" utility included with the
Net::SNMP distribution can be used to create the hexadecimal string (see snmpkey).
Two different hash algorithms are defined by SNMPv3 which can be used by the Security Model for authentication.
These algorithms are HMAC-MD5-96 "MD5" (RFC 1321) and HMAC-SHA-96 "SHA-1" (NIST FIPS PUB 180-1). The default
algorithm used by the module is HMAC-MD5-96. This behavior can be changed by using the --authprotocol argument.
This argument expects either the string 'md5' or 'sha' to be passed to modify the hash algorithm.
By specifying the arguments --privkey or --privpassword the securityLevel associated with the object becomes
'authPriv'. According to SNMPv3, privacy requires the use of authentication. Therefore, if either of these two
arguments are present and the --authkey or --authpassword arguments are missing, the creation of the object
fails. The --privkey and --privpassword arguments expect the same input as the --authkey and --authpassword
arguments respectively.
The User-based Security Model described in RFC 3414 defines a single encryption protocol to be used for privacy.
This protocol, CBC-DES "DES" (NIST FIPS PUB 46-1), is used by default or if the string 'des' is passed to the
--privprotocol argument. By working with the Extended Security Options Consortium http://www.snmp.com/eso/, the
module also supports additional protocols which have been defined in draft specifications. The draft
http://www.snmp.com/eso/draft-reeder-snmpv3-usm-3desede-00.txt defines the support of CBC-3DES-EDE "Triple-DES"
(NIST FIPS 46-3) in the User-based Security Model. This protocol can be selected using the --privprotocol argu-
ment with the string '3desede'. The draft http://www.snmp.com/eso/draft-blumenthal-aes-usm-04.txt describes the
use of CFB128-AES-128/192/256 "AES" (NIST FIPS PUB 197) in the USM. The three AES encryption protocols, differen-
tiated by their key sizes, can be selected by passing 'aescfb128', 'aescfb192', or 'aescfb256' to the -privproto-
col argument.
Details on Filters
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:
"and" (equivalent with "&&")
Boolean "and" of the two expressions, is only true if both expressions are true. Example: expression1 and
expression2
"or" (equivalent with "||")
Boolean "or" of the two expressions, is true if either or both expressions are true. Example: expression1 or
expression2
"not" (equivalent with "!")
Boolean negation of a single expression. Example: not expression . Yet another example: !expression
(For more details on this I recommend a book on Perl)
Predefined Filter Variables
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 ($), which is a syntactic requirement for scalar
variables in Perl. The danger here is that the dollar sign in many shells is an active character (often used for
shell variables exactly as in Perl variables) so it is important to ensure that the Perl expression isn't evalu-
ated by the command line shell as shell code before being passed to cfgmaker as command line arguments. In
shells like Bourne shell, ksh shell or bash shell, placing the entire expression within single qoutes will avoid
such accidental evaluation:
'--if-filter=($default_iftype && $if_admin)'
$if_type
This is an integer specifying the interface type as per the SNMP standards and as reported by the polled
device. A complete list of interface types would be impractical for this document , but there are a number
predefined varables below. Normally, cfgmaker puts in the target's PageTop this iftype value within paran-
thesis after the name of the interface type. (e.g "propPointToPointSerial(22)").
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
$default
True if and only if cfgmaker normally should accepted the interface based on the interfaces administrative
and operational state (taking the flags --no-down and --show-op-down into account) and it's type (and a few
other things).
$default_ifstate
True if and only if cfgmaker would have accepted the interface based on it's operational and administrative
states (also taking into account the presence of the flags --no-down and --show-op-down).
$default_iftype
True if and only if cfgmaker would have accepted the interface based on it's type (and a few type specific
details in addition).
$if_admin
True if and only if the interface is in an adminstrative up state.
$if_oper
True if and only if the interface is in an operational up state.
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.
$if_is_ethernet
True for ethernet interfaces (nr 6, 7, 26, 62, 69 and 117).
$if_is_isdn
True for various ISDN interface types (nr 20, 21, 63, 75, 76 and 77)
$if_is_dialup
True for dial-up interfaces such as PPP as well as ISDN. (nr 23, 81, 82 and 108 in addition to the numbers
of $if_is_isdn).
$if_is_atm
True for miscellaneous ATM related interface types (nr 37, 49, 107, 105, 106, 114 and 134).
$if_is_wan
True for WAN interfaces point to point, Frame Relay and High Speed Serial ( 22,32,44,46)
$if_is_lan
True for LAN interfaces (8, 9, 11, 15, 26, 55, 59, 60 and 115 in addition to the numbers of $if_is_ethernet).
$if_is_dsl
True for ADSL, RDSL, HDSL and SDSL (nr 94, 95, 96, 97)
$if_is_loopback
True for software loopback interfaces (nr 24)
$if_is_ciscovlan
True for Cisco VLAN interfaces (interfaces with the word Vlan or VLAN in their ifdescs)
$if_vlan_id
Returns the vlan id associated with a specific port on Cisco Catalyst switches under both Catalyst OS and
IOS. If it is not a vlan interface, will return undef.
$if_MTU
Returns the Maximum Transfer Unit associated with a specific port.
Besides that, you can also use the variables defined for templates below. Further, all the variables available
in cfgmaker is at the scripts disposal even if the use of such features is discouraged. More "shortcuts" in the
form of variables and functions will be made avaiable in the future instead.
Examples on Filters
The following filter will not affect which interfaces get's included or excluded, it will make cfgmaker behave as
normally.
'--if-filter=$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'
Details on Templates
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).
Writable Template Variables
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.
$target_lines
This variable is the placeholder for the configuration lines created by the template. $target_lines is pre-
defined to be empty when the template code is evaluated.
$head_lines
This variable is intended to be the placeholder for the comment line appearing just before the target in the
configuration file. It is initialized with that comment line before the evaluation of the template code and
if the template doesn't modify $head_lines during evaluation, the comment will look like usual in the config
file.
$problem_lines
This variable is intended to be the placholder for the comment lines describing any problems which might have
been encountered when trying to add the target into the configuration. For host templates it's normally not
used and for those it's predefined as the empty string. For interface templates $problem_lines is predefined
with the error description comments which cfgmaker normally would use for rejected interfaces or as the empty
string for accepted interfaces.
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.
$separator_lines
This variable is the placeholder for the string to use as the separator between the code for individual tar-
gets. The contents of this variable is put after each target (so the lines will appear after the end of the
last target in the config as well).
Predefined Template Variables
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.
Host and System Variables
$router_name
This is the fully qualified name for the router. It is affected by the following items on the command line:
the router name itself and --dns-domain.
$router_connect
This is the reference string for the router being polled. It is on the form community@router possibly fol-
lowed by some snmp options. It is affected by the following items on the command line: the router name
itself, --community, --snmp-options and --dns-domain. (There's no HTML escaped variant available)
$directory_name
This variable should contain the directory name as cfgmaker normally would use as the value for the "Direc-
tory[]" directive. The value is determined by the --subdirs command line option. If --subdirs isn't speci-
fied $directory_name will be the empty string. (There's no HTML escaped variant available)
$syscontact
This variable is the router's SNMP sysContact value. (HTML escaped variant: $html_syscontact)
$sysname
This variable is the router's SNMP sysName value. (No HTML escaped variant available)
$syslocation
This variable is the router's SNMP sysLocation value. (HTML escaped variant: $html_syslocation)
$sysdescr
This variable is the router's SNMP sysDescr value. It is normally not used by cfgmaker but might be useful
in a template. (HTML escaped variant: $html_sysdescr)
Interface Target Related Variables
$target_name
This is what cfgmaker normally would use as the the name of the target. The target name is what is found
within the square brackets, "[]", for target directives. (There's no HTML escaped variant available)
$if_ref
This the reference string for the interface. It is expected to be used in the "Target[xyz]" directive to
distinguish what interface to use. The value of this variable is affected by the --ifref command line
option. It is normally used together with $router_connect. (There's no HTML escaped variant available)
$if_ok
This variable is true if the interface is going to be included into the configuration file, otherwise false.
Don't test against other variables such as $problem_lines to find out if an interface will be rejected or
not, use this $if_ok instead.
$default_target_lines
This variable contains all the target lines which cfgmaker by default outputs for this interface. It's use-
ful if you want to have the "standard target" but want to add some extra lines to it by using a template.
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.
$default_target_directive
This variable contains the default string for the Target[] directive line.
$default_setenv_directive
This variable contains the default string for the SetEnv[] directive line.
$default_directory_directive
This variable contains the default string for the Directory[] directive line which means it is an empty
string (with no newline) if there's no directory.
$default_maxbytes_directive
This variable contains the default string for the MaxBytes[] directive line.
$default_title_directive
This variable contains the default string for the Title[] directive line.
$default_pagetop_directive
This variable contains the default string for the PageTop[] directive lines.
Interface Network Configuration Variables
$if_ip
This variable should contain the IP-address of the interface, if any has been assigned to it. (There's no
HTML escaped variant available)
$ifindex
This variable is the SNMP ifIndex for the interface which per definition always is an integer. (There's no
HTML escaped variant available)
$if_index
Equivalent with $ifindex.
$if_eth
Contains the ethernet address of the interface, if any. (There's no HTML escaped variant available)
$if_speed
This variable is the speed in bytes/second (with prefixes). (There's no HTML escaped variant available)
$if_speed_str
This variable is a cooked speed description which is either in bits or bytes depending on wether or not the
bits option is active and also with the proper prefix for the speed (k, M, G etc). (No HTML escaped variant
available)
$if_type_desc
This variable is a textual description of the interface type. (HTML escaped variant: $html_if_type_desc)
$if_type_num
This variable the integer value corresponding to the interface type (for a listing for the value for the more
common interface types, see the section DETAILS ON FILTERS above). (No HTML escaped variant available)
$if_dns_name
This is the DNS name for the interface. (No HTML escaped variant available)
Interface Name, Description and Alias Variables
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.
$if_snmp_descr
This variable should contain the "raw" description of the interface as determined by the SNMP polling of the
router. (HTML escaped variant: $html_if_snmp_descr)
$if_snmp_name
The "raw" name for the interface as provided by SNMP polling. (HTML escaped variant: $html_if_snmp_name)
$if_snmp_alias
The "raw" ifAlias for the interface as provided by SNMP polling. (HTML escaped variant: $html_if_snmp_alias)
$if_cisco_descr
The "raw" CiscolocIfDescr for the interface as provided by SNMP polling. (HTML escaped variant:
$html_if_cisco_descr)
$if_description
This is the "cooked" description string for the interface, taking into account the SNMP values found for the
interface's RDescr, ifAlias and CiscolocIfDescr. (HTML escaped variant: $html_if_description)
$if_title
The full string cfgmaker by default would have used for the Title[] directive in the configuration as well as
the content of the topmost H1 tag in the PageTop[]. Is composed by the contents of $desc_prefix,
$if_title_desc and $sysname.
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_port_name
If the host is a Cisco Catalyst LAN switch, this variable is the name of that port. (No HTML escaped variant
available)
$desc_prefix
This variable is a prefix of the description of what the target is to use in the "Title[]" directive and in
the H1 section of the "PageTop[]". Default is "Traffic analysis for ". (HTML escaped variant:
$html_desc_prefix)
$if_title_desc
This is the description of the interface normally used by cfgmaker as part of the variable $if_title. The
latter is used as the full string in the "Title[]" directove and the H1 section in the PageTop[].
$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)
Help Functions for Templates
The following functions exists to facilitate the writing of host and interface templates.
html_escape(string)
html_escape() takes a string as an argument and returns a new string where the following substitutions has
been done: the chars "<", ">" and "&" are replaced by "<", ">" and "&" and that newlines embedded
in the string are prepended with "<BR>" and appended with a space character (newlines at the end of the
string are not touched).
Example Template Files
Template Example 1: Eliminating Rejected Targets From Appearing
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 -- $sysname</h1>
<div id="sysdetails">
<table>
<tr>
<td>System:</td>
<td>$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>
</div>
ECHO
} else {
$head_lines="";
$problem_lines="";
$target_lines="";
$separator_lines="";
}
Template Example 2: Simplier Version of Example 1
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="";
}
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>$router_name CPU load</h1>
<div>
<table>
<tr>
<td>System:</td>
<td>$router_name in $html_syslocation</td>
</tr>
<tr>
<td>Maintainer:</td>
<td>$html_syscontact</td>
</tr>
<tr>
<td>Description:</td>
<td>$html_sysdescr</td>
</tr>
<tr>
<td>Resource:</td>
<td>CPU.</td>
</tr>
</table>
</div>
ECHO
EXAMPLES
The first example creates a config file for router.place.xyz: the router has the community name public. Inter-
faces 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 sin-
gle line.
cfgmaker --global "WorkDir: /home/tobi" \
--global "Options[_]: growright,bits" \
--ifref=ip \
public@router.place.xyz > mrtg.cfg
Note: if cfgmaker is not in your path, but you are in the directory where cfgmaker is stored, you can start it
with ./cfgmaker
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 \
public@router1.place.xyz \
public@router2.place.xyz \
--global "Options[_]: growright" \
--ifref=name \
--ifdesc=descr \
public@switch1.place.xyz \
--ifdesc=name \
public@switch2.place.xyz > 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 ver-
sion 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 \
access@ppp-server.remote:::::1 > mrtg.cfg
RELATED
mrtg-reference
LICENSE
GNU General Public License
COPYRIGHT
Cfgmaker is Copyright 2000 by Tobias Oetiker <tobi@oetiker.ch>
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