Hi Paul,
Certainly, you cannot make a precise estimation how many packets
have been lost.
But as consumer of the exported flow information I would be
highly interested how long a router was restarting. Whether or
noit I can use this information for an estimate depends a lot
on the scenario.
Sujay,
Do you assume that the router is still forwarding packets
while restarting ?
Thanks,
Juergen
On 21.10.09 20:52 "Paul Aitken" <paitken at cisco.com> wrote:
> sujay,
>
>> So what I am proposing ( and is possible) is that under these
>> conditions like O/L , soft restart the system (switch/router) can
>> easily send to the collector at least the "duration under which it
>> was in the O/L/reset condition" . This information I am thinking would
>> be useful as a rough estimate of monitoring lost, canbe converted in
>> to number of packets not accounted for
>
> No, it can't.
>
> There are too many variables which the collecting process would have to
> know. eg how many active monitoring processes are there on the exporting
> device, and how much traffic are they each measuring on average?
>
> The delay between measuring and exporting, and the flow lifetime on the
> switch will also be relevant, since you'll export some partially filled
> flows for some period of time after the reset.
>
>
>> or may be used as an unaccounted period by the collector.
>
> I think that's the only possibility. Let's not try to guess how much
> traffic was lost.
>
> Cheers,
> P.
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