|
Packit |
667938 |
.\" Automatically generated by Pod::Man 2.28 (Pod::Simple 3.29)
|
|
Packit |
667938 |
.\"
|
|
Packit |
667938 |
.\" Standard preamble:
|
|
Packit |
667938 |
.\" ========================================================================
|
|
Packit |
667938 |
.de Sp \" Vertical space (when we can't use .PP)
|
|
Packit |
667938 |
.if t .sp .5v
|
|
Packit |
667938 |
.if n .sp
|
|
Packit |
667938 |
..
|
|
Packit |
667938 |
.de Vb \" Begin verbatim text
|
|
Packit |
667938 |
.ft CW
|
|
Packit |
667938 |
.nf
|
|
Packit |
667938 |
.ne \\$1
|
|
Packit |
667938 |
..
|
|
Packit |
667938 |
.de Ve \" End verbatim text
|
|
Packit |
667938 |
.ft R
|
|
Packit |
667938 |
.fi
|
|
Packit |
667938 |
..
|
|
Packit |
667938 |
.\" Set up some character translations and predefined strings. \*(-- will
|
|
Packit |
667938 |
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
|
|
Packit |
667938 |
.\" double quote, and \*(R" will give a right double quote. \*(C+ will
|
|
Packit |
667938 |
.\" give a nicer C++. Capital omega is used to do unbreakable dashes and
|
|
Packit |
667938 |
.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
|
|
Packit |
667938 |
.\" nothing in troff, for use with C<>.
|
|
Packit |
667938 |
.tr \(*W-
|
|
Packit |
667938 |
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
|
|
Packit |
667938 |
.ie n \{\
|
|
Packit |
667938 |
. ds -- \(*W-
|
|
Packit |
667938 |
. ds PI pi
|
|
Packit |
667938 |
. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
|
|
Packit |
667938 |
. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
|
|
Packit |
667938 |
. ds L" ""
|
|
Packit |
667938 |
. ds R" ""
|
|
Packit |
667938 |
. ds C` ""
|
|
Packit |
667938 |
. ds C' ""
|
|
Packit |
667938 |
'br\}
|
|
Packit |
667938 |
.el\{\
|
|
Packit |
667938 |
. ds -- \|\(em\|
|
|
Packit |
667938 |
. ds PI \(*p
|
|
Packit |
667938 |
. ds L" ``
|
|
Packit |
667938 |
. ds R" ''
|
|
Packit |
667938 |
. ds C`
|
|
Packit |
667938 |
. ds C'
|
|
Packit |
667938 |
'br\}
|
|
Packit |
667938 |
.\"
|
|
Packit |
667938 |
.\" Escape single quotes in literal strings from groff's Unicode transform.
|
|
Packit |
667938 |
.ie \n(.g .ds Aq \(aq
|
|
Packit |
667938 |
.el .ds Aq '
|
|
Packit |
667938 |
.\"
|
|
Packit |
667938 |
.\" If the F register is turned on, we'll generate index entries on stderr for
|
|
Packit |
667938 |
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
|
|
Packit |
667938 |
.\" entries marked with X<> in POD. Of course, you'll have to process the
|
|
Packit |
667938 |
.\" output yourself in some meaningful fashion.
|
|
Packit |
667938 |
.\"
|
|
Packit |
667938 |
.\" Avoid warning from groff about undefined register 'F'.
|
|
Packit |
667938 |
.de IX
|
|
Packit |
667938 |
..
|
|
Packit |
667938 |
.nr rF 0
|
|
Packit |
667938 |
.if \n(.g .if rF .nr rF 1
|
|
Packit |
667938 |
.if (\n(rF:(\n(.g==0)) \{
|
|
Packit |
667938 |
. if \nF \{
|
|
Packit |
667938 |
. de IX
|
|
Packit |
667938 |
. tm Index:\\$1\t\\n%\t"\\$2"
|
|
Packit |
667938 |
..
|
|
Packit |
667938 |
. if !\nF==2 \{
|
|
Packit |
667938 |
. nr % 0
|
|
Packit |
667938 |
. nr F 2
|
|
Packit |
667938 |
. \}
|
|
Packit |
667938 |
. \}
|
|
Packit |
667938 |
.\}
|
|
Packit |
667938 |
.rr rF
|
|
Packit |
667938 |
.\"
|
|
Packit |
667938 |
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
|
|
Packit |
667938 |
.\" Fear. Run. Save yourself. No user-serviceable parts.
|
|
Packit |
667938 |
. \" fudge factors for nroff and troff
|
|
Packit |
667938 |
.if n \{\
|
|
Packit |
667938 |
. ds #H 0
|
|
Packit |
667938 |
. ds #V .8m
|
|
Packit |
667938 |
. ds #F .3m
|
|
Packit |
667938 |
. ds #[ \f1
|
|
Packit |
667938 |
. ds #] \fP
|
|
Packit |
667938 |
.\}
|
|
Packit |
667938 |
.if t \{\
|
|
Packit |
667938 |
. ds #H ((1u-(\\\\n(.fu%2u))*.13m)
|
|
Packit |
667938 |
. ds #V .6m
|
|
Packit |
667938 |
. ds #F 0
|
|
Packit |
667938 |
. ds #[ \&
|
|
Packit |
667938 |
. ds #] \&
|
|
Packit |
667938 |
.\}
|
|
Packit |
667938 |
. \" simple accents for nroff and troff
|
|
Packit |
667938 |
.if n \{\
|
|
Packit |
667938 |
. ds ' \&
|
|
Packit |
667938 |
. ds ` \&
|
|
Packit |
667938 |
. ds ^ \&
|
|
Packit |
667938 |
. ds , \&
|
|
Packit |
667938 |
. ds ~ ~
|
|
Packit |
667938 |
. ds /
|
|
Packit |
667938 |
.\}
|
|
Packit |
667938 |
.if t \{\
|
|
Packit |
667938 |
. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
|
|
Packit |
667938 |
. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
|
|
Packit |
667938 |
. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
|
|
Packit |
667938 |
. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
|
|
Packit |
667938 |
. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
|
|
Packit |
667938 |
. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
|
|
Packit |
667938 |
.\}
|
|
Packit |
667938 |
. \" troff and (daisy-wheel) nroff accents
|
|
Packit |
667938 |
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
|
|
Packit |
667938 |
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
|
|
Packit |
667938 |
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
|
|
Packit |
667938 |
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
|
|
Packit |
667938 |
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
|
|
Packit |
667938 |
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
|
|
Packit |
667938 |
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
|
|
Packit |
667938 |
.ds ae a\h'-(\w'a'u*4/10)'e
|
|
Packit |
667938 |
.ds Ae A\h'-(\w'A'u*4/10)'E
|
|
Packit |
667938 |
. \" corrections for vroff
|
|
Packit |
667938 |
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
|
|
Packit |
667938 |
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
|
|
Packit |
667938 |
. \" for low resolution devices (crt and lpr)
|
|
Packit |
667938 |
.if \n(.H>23 .if \n(.V>19 \
|
|
Packit |
667938 |
\{\
|
|
Packit |
667938 |
. ds : e
|
|
Packit |
667938 |
. ds 8 ss
|
|
Packit |
667938 |
. ds o a
|
|
Packit |
667938 |
. ds d- d\h'-1'\(ga
|
|
Packit |
667938 |
. ds D- D\h'-1'\(hy
|
|
Packit |
667938 |
. ds th \o'bp'
|
|
Packit |
667938 |
. ds Th \o'LP'
|
|
Packit |
667938 |
. ds ae ae
|
|
Packit |
667938 |
. ds Ae AE
|
|
Packit |
667938 |
.\}
|
|
Packit |
667938 |
.rm #[ #] #H #V #F C
|
|
Packit |
667938 |
.\" ========================================================================
|
|
Packit |
667938 |
.\"
|
|
Packit |
667938 |
.IX Title "MRTG-FAQ 1"
|
|
Packit |
667938 |
.TH MRTG-FAQ 1 "2018-07-13" "2.17.7" "mrtg"
|
|
Packit |
667938 |
.\" For nroff, turn off justification. Always turn off hyphenation; it makes
|
|
Packit |
667938 |
.\" way too many mistakes in technical documents.
|
|
Packit |
667938 |
.if n .ad l
|
|
Packit |
667938 |
.nh
|
|
Packit |
667938 |
.SH "NAME"
|
|
Packit |
667938 |
mrtg\-faq \- How to get help if you have problems with MRTG
|
|
Packit |
667938 |
.SH "SYNOPSIS"
|
|
Packit |
667938 |
.IX Header "SYNOPSIS"
|
|
Packit |
667938 |
\&\s-1MRTG\s0 seems to raise a lot of questions. There are a number of resources
|
|
Packit |
667938 |
apart from the documentation where you can find help for mrtg.
|
|
Packit |
667938 |
.SH "FAQ"
|
|
Packit |
667938 |
.IX Header "FAQ"
|
|
Packit |
667938 |
In the following sections you'll find some additonal Frequently Asked Questions, with Answers.
|
|
Packit |
667938 |
.ie n .SS "Why is there no ""@#$%"" (my native language) version of \s-1MRTG\s0?"
|
|
Packit |
667938 |
.el .SS "Why is there no ``@#$%'' (my native language) version of \s-1MRTG\s0?"
|
|
Packit |
667938 |
.IX Subsection "Why is there no @#$% (my native language) version of MRTG?"
|
|
Packit |
667938 |
Nobody has contributed a \fI@#$%.pmd\fR file yet. Go into the
|
|
Packit |
667938 |
\&\fImrtg\-2.17.7/translate\fR directory and create your own translation file.
|
|
Packit |
667938 |
When you are happy with it send it to me for inclusion with the next mrtg
|
|
Packit |
667938 |
release.
|
|
Packit |
667938 |
.SS "I need a script to make mrtg work with my xyz device."
|
|
Packit |
667938 |
.IX Subsection "I need a script to make mrtg work with my xyz device."
|
|
Packit |
667938 |
Probably this has already been done. Check the stuff in the
|
|
Packit |
667938 |
\&\fImrtg\-2.17.7/contrib\fR directory. There is a file called \fI00INDEX\fR in
|
|
Packit |
667938 |
that directory which tells what you can find in there.
|
|
Packit |
667938 |
.SS "How does this \s-1SNMP\s0 thing work"
|
|
Packit |
667938 |
.IX Subsection "How does this SNMP thing work"
|
|
Packit |
667938 |
There are many resources on the net that explain \s-1SNMP.\s0
|
|
Packit |
667938 |
Take a look at this article from the Linux Journal by David Guerrero
|
|
Packit |
667938 |
.PP
|
|
Packit |
667938 |
.Vb 1
|
|
Packit |
667938 |
\& http://www.david\-guerrero.com/papers/snmp/
|
|
Packit |
667938 |
.Ve
|
|
Packit |
667938 |
.PP
|
|
Packit |
667938 |
And at this rather long document from \s-1CISCO.\s0
|
|
Packit |
667938 |
.PP
|
|
Packit |
667938 |
.Vb 1
|
|
Packit |
667938 |
\& http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/snmp.htm
|
|
Packit |
667938 |
.Ve
|
|
Packit |
667938 |
.SS "The images created by \s-1MRTG\s0 look very strange."
|
|
Packit |
667938 |
.IX Subsection "The images created by MRTG look very strange."
|
|
Packit |
667938 |
Remove the *\-{week,day,month,year}.png files and start \s-1MRTG\s0
|
|
Packit |
667938 |
again. Using \s-1MRTG\s0 for the first time, you might have to do this
|
|
Packit |
667938 |
twice. This will also help when you introduce new routers into the cfg
|
|
Packit |
667938 |
file.
|
|
Packit |
667938 |
.SS "What is my Community Name?"
|
|
Packit |
667938 |
.IX Subsection "What is my Community Name?"
|
|
Packit |
667938 |
Ask the person in charge of your Router or try 'public', as this is the
|
|
Packit |
667938 |
default Community Name.
|
|
Packit |
667938 |
.SS "My graphs show a flat line during an outage. Why ?"
|
|
Packit |
667938 |
.IX Subsection "My graphs show a flat line during an outage. Why ?"
|
|
Packit |
667938 |
Well, the short answer is that when an \s-1SNMP\s0 query goes out
|
|
Packit |
667938 |
and a response doesn't come back, \s-1MRTG\s0 has to assume something to put
|
|
Packit |
667938 |
in the graph, and by default it assumes that the last answer we got
|
|
Packit |
667938 |
back is probably closer to the truth than zero. This assumption is
|
|
Packit |
667938 |
not perfect (as you have noticed). It's a trade-off that happens to
|
|
Packit |
667938 |
fail during a total outage.
|
|
Packit |
667938 |
.PP
|
|
Packit |
667938 |
If this is an unacceptable trade-off, use the \fBunknaszero\fR option.
|
|
Packit |
667938 |
.PP
|
|
Packit |
667938 |
You may want to know what you're trading off, so in the spirit of
|
|
Packit |
667938 |
trade-offs, here's the long answer:
|
|
Packit |
667938 |
.PP
|
|
Packit |
667938 |
The problem is that \s-1MRTG\s0 doesn't know *why* the data didn't come back, all
|
|
Packit |
667938 |
it knows is that it didn't come back. It has to do something, and it
|
|
Packit |
667938 |
assumes it's a stray lost packet rather than an outage.
|
|
Packit |
667938 |
.PP
|
|
Packit |
667938 |
Why don't we always assume the circuit is down and use zero, which will
|
|
Packit |
667938 |
(we think) be more nearly right? Well, it turns out that you may be
|
|
Packit |
667938 |
taking advantage of \s-1MRTG\s0's \*(L"assume last\*(R" behaviour without being aware of
|
|
Packit |
667938 |
it.
|
|
Packit |
667938 |
.PP
|
|
Packit |
667938 |
\&\s-1MRTG\s0 uses \s-1SNMP \s0(Simple Network Management Protocol) to collect data, and
|
|
Packit |
667938 |
\&\s-1SNMP\s0 uses \s-1UDP \s0(User Datagram Protocol) to ship packets around. \s-1UDP\s0 is
|
|
Packit |
667938 |
connectionless (not guaranteed) unlike \s-1TCP\s0 where packets are tracked and
|
|
Packit |
667938 |
acknowledged and, if needed, retransmitted. \s-1UDP\s0 just throws
|
|
Packit |
667938 |
packets at the network and hopes they arrive. Sometimes they don't.
|
|
Packit |
667938 |
.PP
|
|
Packit |
667938 |
One likely cause of lost \s-1SNMP\s0 data is congestion; another is busy routers.
|
|
Packit |
667938 |
Other possibilities include transient telecommunications problems, router
|
|
Packit |
667938 |
buffer overflows (which may or may not be congestion-related), \*(L"dirty
|
|
Packit |
667938 |
lines\*(R" (links with high error rates), and acts of God. These things
|
|
Packit |
667938 |
happen all the time; we just don't notice because many interactive
|
|
Packit |
667938 |
services are TCP-based and the lost packets get retransmitted
|
|
Packit |
667938 |
automatically.
|
|
Packit |
667938 |
.PP
|
|
Packit |
667938 |
In the above cases where some \s-1SNMP\s0 packets are lost but traffic is
|
|
Packit |
667938 |
flowing, assuming zero is the wrong thing to do \- you end up with a graph
|
|
Packit |
667938 |
that looks like it's missing teeth whenever the link fills up. \s-1MRTG\s0
|
|
Packit |
667938 |
interpolates the lost data to produce a smoother graph which is more
|
|
Packit |
667938 |
accurate in cases of intermittent packet loss. But with V2.8.4 and above,
|
|
Packit |
667938 |
you can use the \*(L"unknaszero\*(R" option to produce whichever graph is best
|
|
Packit |
667938 |
under the conditions typical for your network.
|
|
Packit |
667938 |
.SH "AUTHOR"
|
|
Packit |
667938 |
.IX Header "AUTHOR"
|
|
Packit |
667938 |
Tobias Oetiker <tobi@oetiker.ch>
|