Are you using any fancy features (Rate-limit, etc..?) on the interface
in question? There was one bug I saw in IOS whereby it would report
2+Gb/s on any interface with rate-limit configured amongst other
issues. I'm not aware of any of those existing in current software
versions but they did exist in the past (somewhere around 12.0.14S->12.0.17S)
The interface may also be taking into account 95% type information
as far as bit rates, which mrtg may not pick up any 2-5 second bursts but
the statistics collector within IOS may pick up also. I suspect that is
what is really going on.
- Jared
On Tue, Nov 13, 2001 at 12:30:51PM -0500, Deepak Jain wrote:
>
> If I remember correctly, Cisco uses some kind of decaying average algorithm
> to report bit rate/second on interfaces.
>
> MRTG and programs like it use regular polling of byte counters. If the
> latency of the network is constant and both the statistics machine and the
> network device have sufficient available CPU, it seems to me that MRTG
> statistics will be more accurate over a 5 minute window.
>
> The reason I am asking is because I have a full duplex FE interface that is
> reporting 94mb/s inbound on a 5 minute average, and yet the MRTG is never
> exceeding 84.2mb/s on the same interface. [MRTG is configured as a daemon so
> cron-timing shouldn't be an issue]
>
> Information and suggestions are appreciated.
>
> Thanks in advance,
>
> Deepak Jain
> AiNET
-- Jared Mauch | pgp key available via finger from jared@puck.nether.net clue++; | http://puck.nether.net/~jared/ My statements are only mine.
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