[mrtg] How mrtg counts used bandwith?

[Alexey V. Panfilov]

Thank you, Yves!

It works. MRTG uses ifHC* OIDs for snmpv2.

>
> Alexey,
>
> You're right. For line speed above 100Mbps, you have to use the snmpv2 
> extendend 64 bits counters.
> see http://oss.oetiker.ch/mrtg/doc/mrtg-reference.en.html at the 
> snmpv2c section.
>
> Regards,
>
> Yves Claessens
>
>
>
>
>
>
> Hi everyone!
>
> I've the question: how mrtg counts used bandwidth of high-loaded ports?
>
> AFAIK, mrtg uses ifInOctets.PORT_NUM and ifOutOctets.PORT_NUM OIDs.
> For example, I've Cisco3560G and I got next result:
> IF-MIB::ifOutOctets.10128 = Counter32: 1751739669
> but Counter32 can have maximum value of 2^32-1.
> So, if I've traffic around 1Gbit/sec on this port Counter will reset to
> zero around 30 sec, but mrtg collects data every 5 min...
>
> Please, explain me mrtg's algorithm...
>
> 


-- 
Best regards, Alexey V. Panfilov
ICQ: 1053180
Jabber: lehis at jabber.ru
mailto: ports at subnets.ru
www: http://www.subnets.ru