[mrtg] [FORGED] MRTG and IT Watchdog sensor

Roger Smith rogertcoe at gmail.com
Tue Nov 24 17:44:56 CET 2015

I also tried the OID themselves:

Target[]: at

I got:
2015-11-24 08:44:18 -- SNMP Error:
receiving response PDU: An existing connection was forcibly closed by the
remote host.
SNMPv1_Session (remote host: "" [].161)
                  community: "tcoe-snmp"
                 request ID: 1669607121
                PDU bufsize: 8000 bytes
                    timeout: 2s
                    retries: 5
                    backoff: 1)
 at c:/mrtg/bin\..\lib\mrtg2/SNMP_util.pm line 497
2015-11-24 08:44:18 -- SNMPGET Problem for sysUptime sysName on tcoe-snmp at
 at c:\mrtg\bin\mrtg line 2330
2015-11-24 08:44:18 -- 2015-11-24 08:44:18: ERROR:
Target[][_IN_] ' $target->[0]{$mode} ' did not eval into
defined data
2015-11-24 08:44:18 -- 2015-11-24 08:44:18: ERROR:
Target[][_OUT_] ' $target->[0]{$mode} ' did not eval into
defined data

Date: Fri, 20 Nov 2015 21:36:46 +0000
From: Steve Shipway <s.shipway at auckland.ac.nz>
To: Roger Smith <rogertcoe at gmail.com>, "mrtg at lists.oetiker.ch"
        <mrtg at lists.oetiker.ch>
Subject: Re: [mrtg] [FORGED]  MRTG and IT Watchdog sensor
5820DC553954E44FA1A36C78323AD148A3F955F5 at uxcn10-6.UoA.auckland.ac.nz>
Content-Type: text/plain; charset="iso-8859-1"

Target[]: tempSensorTemp:tcoe-snmp at
<mailto:tempSensorTemp%3Atcoe-snmp at>

You must always give exactly two metrics to MRTG per Target (this is
historical, because originally this was inbound and outbound data for
network traffic).  If it is a single value, either duplicate it, or use

tempSensorTemp&pseudoZero:tcoe-snmp at<mailto:
tempSensorTemp%3Atcoe-snmp at>

This is also assuming, of course, that the symbolic name tempSensorTemp can
be expanded to an OID; for this to work, you need to have the MIB properly
installed or referred to in the MRTG config file.  Otherwise, you can
always use the numerical OID instead.

Now, your OID actually returns the value in deci-degrees, so you need to
divide by 10 before storing to make the value an SI unit (Best Practice is
to store values as SI units).

tempSensorTemp&pseudoZero:tcoe-snmp at  /  10
<mailto:tempSensorTemp%3Atcoe-snmp at>

The spaces around the '/' are required.  This will mean the value is stored
in degrees, and will display the correct numbers.  However, if you are not
using RRDTool and are just using native MRTG, decimals are not supported in
the backend storage, and so you might instead need to do

Factor[]: 0.1

... which will divide by 10 at graphing time instead.

Since you do not want to graph the second item, just use the 'noo' ('No
outgoing') option to suppress it.

Options[]: gauge growright noo



Steve Shipway
University of Auckland ITS
UNIX Systems Design Lead
s.shipway at auckland.ac.nz<mailto:s.shipway at auckland.ac.nz>
Ph: +64 9 373 7599 ext 86487

Roger Smith
Director, Information Systems
Tulare County Office of Education
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.oetiker.ch/pipermail/mrtg/attachments/20151124/7191d9b3/attachment-0001.html>

More information about the mrtg mailing list