[mrtg] Wrong Values

[Freddie Cash]

On February 27, 2009 11:12 am mikelowrey wrote:
> How can I find out if the 64bit counters are available and how can I
> change this Target entries?

snmpwalk -v 2c -c <communitystring> <server.address>

That will connect via SNMP to <server.address> and list all the SNMP MIB 
entries that it knows about.  You can redirect that to a file (> snmp.txt) 
or just pipe it through grep (| grep 64).

You can tell it to "walk" portions of the MIB space, so that it only shows 
you certain entries.  If you want to see everything in the if* MIB, then 
use:

snmpwalk -v 2c -c <community> <server.address> if

Look for entries like Counter64.  Those are 64-bit counters.  Compared to 
Counter32 which are the 32-bit counters.

> Polling:
> Do I just need to change my crontab entry to every minute instead of
> every 5 minutes or do I need to change more?
> Thanks and sorry for beginner questions.

The lowest poll interval that standard MRTG logging can handle is 5 minutes.  
If you want to go below this, you have to change the MRTG LogFormat to rrd.  
This turns MRTG into *just* a data collector.  You cannot use standard MRTG 
to *view* the data collected in RRD format.  You have to install and use a 
front-end like mrtg-rrd, 14all.cgi, routers2.cgi, and similar.

There are links and details on this available on the docs page on the main 
mrtg site.  That's where I learnt everything regarding mrtg, rrd, 64-bit 
counters, and so on.  I started out with mrtg-rrd, moved to 14all.cgi, and 
have settled on routers2.cgi as the graphing/viewing front-end.

-- 
Freddie
fjwcash at gmail.com