cfgmaker(1)
NAME
cfgmaker - Creates mrtg.cfg files (for mrtg-2.17.4)
SYNOPSIS
cfgmaker [options] [community@]router [[options] [community@]router ...]
OPTIONS
--ifref=name interface references by Interface Name (default)
--ifref=ip ... by Ip Address
--ifref=eth ... by Ethernet Number
--ifref=descr ... by Interface Description
--ifref=nr ... by Interface Number
--ifref=type ... by Interface Type
You may also use multiple options separated by commas,
in which case the first available one is used:
e.g. --ifref=ip,name,nr
--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=ppname ... uses Passport Port Name
--ifdesc=alias ... uses Interface Alias
--ifdesc=type ... uses Interface Type
You may also use multiple options separated by commas,
in which case the first available one is used:
e.g. --ifdesc=catname,ppname,descr,alias,ip,name,nr
--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 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 you 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.
Note that the first line of the generated cfg file will contain all the
commandline options you used for generating 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 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.
--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 created.
--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.
You can specify multiple properties if you wish, separated by
commas. In this case, cfgmaker will use the first item in the list
which can provide unique identification. This allows you to
specify, for example, to use IP address and to use ifName if this
is not defined:
--ifref ip,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.
You can specify multiple properties if you wish, separated by
commas. In this case, cfgmaker will use the first item in the list
which is available for this interface. This allows you to specify,
for example, to use any of the different aliases in order of
preference.
--if-filter 'filter-expression'
First of all, this is under some development 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 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.
--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 multiple options. The line
will appear in the configuration just before the config for the
next router appearing 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 operationally 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 using the Net:SNMP perl module. There are
optional parameters affecting SNMP operation.
--enablesnmpv3 {yes|no}
The --enablesnmpv3 option is an optional flag to check for the
presence of the Net::SNMP libraries. Cfgmaker will try to
determine whether this flag is required and will set the values
automatically.
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 argument. 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 specified, 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 password 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 argument 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, differentiated by their key sizes, can
be selected by passing 'aescfb128', 'aescfb192', or 'aescfb256' to the
-privprotocol 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 ($),
which is a syntactic requirement for scalar variables in Perl. The
danger here is that the dollar sign in many shells is an active
character (often used for shell variables exactly as in Perl variables)
so it is important to ensure that the Perl expression isn't evaluated
by the command line shell as shell code before being passed to cfgmaker
as command line arguments. In shells like Bourne shell, ksh shell or
bash shell, placing the entire expression within single qoutes will
avoid such accidental evaluation:
'--if-filter=($default_iftype && $if_admin)'
$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 paranthesis 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, and 3Com
switches. If it is not a vlan interface, will return undef.
$if_cisco_trunk
Returns the trunking state of a specific port on Cisco Catalyst
switches under both Catalyst OS and IOS. Returns "1" if the
interface is a trunk, undef otherwise.
$if_MTU
Returns the Maximum Transfer Unit associated with a specific port.
Besides that, you can also use the variables defined for templates
below. Further, all the variables available in cfgmaker is at the
scripts disposal even if the use of such features is discouraged. More
"shortcuts" in the form of variables and functions will be made
available in the future instead.
Examples on Filters
The following filter will not affect which interfaces get's included or
excluded, it will make cfgmaker behave as normally.
'--if-filter=$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 predefined 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 targets. 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 followed 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 "Directory[]" directive.
The value is determined by the --subdirs command line option. If
--subdirs isn't specified $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 useful 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)
$if_pp_port_name
If the host is a Nortel Passport 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: $html_if_title_desc)
Help Functions for Templates
The following functions exists to facilitate the writing of host and
interface templates.
html_escape(string)
html_escape() takes a string as an argument and returns a new
string where the following substitutions has been done: the chars
"<", ">" and "&" are replaced by "<", ">" and "&" and
that newlines embedded in the string are prepended with "<BR>" and
appended with a space character (newlines at the end of the string
are not touched).
oid_pick($router_connect,$v3opt,"oid1","oid2"...)
This function will try to poll each of the oids specified until it
is successful or has run out of oids. It will return the name of
the first oid that worked or undef if it is not successful
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 if defined $if_pp_port_name;
<tr>
<td>Port Name:</td>
<td>$if_pp_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. 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 \
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 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 \
access@ppp-server.remote:::::1 > mrtg.cfg
SEE ALSO
mrtg-reference
AUTHOR
Tobias Oetiker <tobi@oetiker.ch> and Jakob Ilves <jakob.ilves@oracle.com>
LICENSE
GNU General Public License
COPYRIGHT
Cfgmaker is Copyright 2000 by Tobias Oetiker <tobi@oetiker.ch>
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