[mrtg] Measuring (Wan-Out) - (Lan-In) is not working

[Feijo, Fernando]

Thanks, Daniel.


>>>counter roll-overs.  With 32 bit counters, you will have frequent
rollovers.

The speeds in the link stay usually below 40 megs. I am surprised one
can get hit by rollovers so far from the 114-megs threshold, but since
we re doing arithmetic, it could be some internal thing.

Will try the way you suggest.

Fernando



-----Original Message-----
From: mrtg-bounces at lists.oetiker.ch
[mailto:mrtg-bounces at lists.oetiker.ch] On Behalf Of McDonald, Dan
Sent: Wednesday, October 22, 2008 8:04 AM
To: mrtg at lists.oetiker.ch
Subject: Re: [mrtg] Measuring (Wan-Out) - (Lan-In) is not working

On Mon, 2008-10-20 at 00:05 -0400, Feijo, Fernando wrote:
> I was wondering if someone could figure out what is going wrong on 
> this one.
> 

counter roll-overs.  With 32 bit counters, you will have frequent
rollovers.  Now try to do math on two sets of rolling counters - there
is no way to determine if they have rolled or not.

> Thanks if someone can point in the right direction.

The best way to deal with this is to use rrdtool as the backend, and
routers2.cgi as the front end, and do the math on the two RRDs, rather
than the raw counters.


--
Daniel J McDonald, CCIE #2495, CISSP #78281, CNX Austin Energy
http://www.austinenergy.com