[mrtg] Re: End to End measurement of Delay & Packet Loss

[Jonathan Ford]

http://status.ilcso.uiuc.edu/index.plx?newcurrentstatus

I emailed the creator to try to replicate what he's done. He replied with
the following, but I was unable to make it work. Anybody???

The attached CreateRRD.txt file is the DOS command line string I use to
create RRD files that hold the ping information. I create one file for each
device I'm pinging.

c:\rrdtool\rrdtool.exe create c:\rrdtool\ping.rrd DS:RRT:GAUGE:600:U:U
DS:PL:GAUGE:600:U:U RRA:AVERAGE:0.5:1:600 RRA:AVERAGE:0.5:6:700
RRA:AVERAGE:0.5:24:775 RRA:AVERAGE:0.5:288:1895

Every five minutes, I grep the Round-Trip Time (RTT) and Packet Loss (PL)
from a Windows ping command and update the RRD file.

c:\rrdtool\rrdtool.exe update c:\rrdtool\ping.rrd N:128:10

Here's the same thing in Perl:

use RRDs;
$RRDFile = "c:\\rrdtool\\ping.rrd";
RRDs::update ("$RRDFile","N:$Response"); #$Response
is "RRT:PL" from the ping
my $ERR=RRDs::error;
die "ERROR while updating $RRDFile with value $Response:
$ERR\n" if $ERR;

This updates the file with the current time (the "N" variable), 128ms for
the Round-Trip Time (RRT), and 10% for the Packet Loss (PL).

Unlike MRTG, updating the RRD files every five minutes is completely
separate from graphing the information. Below is the Perl script I use to
generate the RRDTool graphs.

use RRDs;
RRDs::graph ("$Graph",
"--start=$Start",
"--title=$Title",
"--vertical-label=Round-Trip Time (ms)",
"--color=BACK#CCCCCC",
"--color=CANVAS#6C9BCD",
"--color=SHADEB#666666",
"--height=125",
"--width=475",
"--lazy",
"--imgformat=GIF",
"--interlaced",
"--units-exponent=0",
"--upper-limit=500",
"--lower-limit=0",
"DEF:RTT=$RRDFile:RTT:AVERAGE",
"DEF:PL=$RRDFile:PL:AVERAGE",
"CDEF:NoPL=PL,10,LE,NEGINF,UNKN,IF",
"CDEF:25PL=PL,25,LE,PL,10,GT,NEGINF,UNKN,IF,UNKN,IF",
"CDEF:50PL=PL,50,LE,PL,25,GT,NEGINF,UNKN,IF,UNKN,IF",
"CDEF:75PL=PL,75,LE,PL,50,GT,NEGINF,UNKN,IF,UNKN,IF",
"CDEF:100PL=PL,100,LE,PL,75,GT,NEGINF,UNKN,IF,UNKN,IF",
"HRULE:500#AA0000",
"COMMENT:$PingFrom to $PingTo\\c",
"COMMENT:\\s",
"COMMENT:     Packet Loss Percentage                          ",
"AREA:RTT#0000AA:Round-Trip Time in milliseconds",
"COMMENT:\\s", "COMMENT:\\s", "COMMENT:        ",
"STACK:NoPL#6C9BCD:  0-10%
",
"GPRINT:RTT:LAST:Current\\:%4.0lf ms",
"COMMENT:\\s", "COMMENT:\\s", "COMMENT:        ",
"STACK:25PL#FFFF00: 10-25%
",
"GPRINT:RTT:AVERAGE:Average\\:%4.0lf ms",
"COMMENT:\\s", "COMMENT:\\s", "COMMENT:        ",
"STACK:50PL#FFCC66: 25-50%
",
"GPRINT:RTT:MAX:Max\\:%4.0lf ms",
"COMMENT:\\s", "COMMENT:\\s", "COMMENT:        ",
"STACK:75PL#FF9900: 50-75% ",
"COMMENT:\\s", "COMMENT:\\s", "COMMENT:        ",
"STACK:100PL#FF0000:75-100% ",
"COMMENT:\\s", "COMMENT:\\s",
"COMMENT:Graph Updated: $Time \\r"
);

----- Original Message -----
From: "Patrick Bartkus" <patrckb at hotmail.com>
To: <roger.leitch at blueyonder.co.uk>; <mrtg at list.ee.ethz.ch>
Sent: Friday, August 17, 2001 12:51 PM
Subject: [mrtg] Re: End to End measurement of Delay & Packet Loss


>
>
> >"Roger Leitch" <roger.leitch at blueyonder.co.uk> wrote:
> >...
> >I need to be able to measure end to end performance across a network with
> >Cisco Routers.
> >
> >I understand that there is a performance measurement system built into
the
> >router IOS that can be configured to send test packets to destination
> >routers.  (Configured using rtr commands).
> >Looking at the MIB: CISCO-RTTMON-MIB.my, it should be possible to
retrieve
> >the results using SNMP.
>
> Roger,
>
> This is asked about every 6 months or so. The short answer is no.
>
> The long answer is that while RTT looks like a neat feature to be able to
> use, it would take a lot of work to make it work.
>
> You have to create a probe in the router & tell it what to probe, how to
> probe it,  how often to probe it, and when to start to probing it. Then
you
> have to go back and query that probe for it's results. All of this is no
> small coding task. CiscoWorks 2000 has a module (Internetwork Performance
> Monitor) written in Java that does all this.
>
> Most people use the MRTG ping probe script and are happy with its results.
>
> If you do set something up using RTT, please post how you do it to this
> list. We would love to hear of your experience.
>
> HTH,
> Patrick
> ---
> Patrick Bartkus, SCE, CCNP, CCDA Certified Sr. Network Support Analyst
> Washington Mutual Home Loans, Inc (Formerly Fleet Mortgage)Columbia, SC
> If truth was not absolute, how could there be justice?
>
>
>
>
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