[j-nsp] recommended Netflow sampling rates?

[Justin M. Streiner]

On Mon, 1 Sep 2008, Alexander Tarkhov wrote:

> This sampling story can be implemented in two different ways on M/T-series.
> One way of configuring the sampling output stanza is to utilize RE
> resources for exporting flows. That is the default (and free) approach
> when one of the daemons on RE - sampled - is doing the job of
> aggregating flows and sending them out via UDP.
>
> The other way of doing this is using services PIC (or some variant of
> it) with JFlow license installed for this purpose.
>
> The limitations of these two options are quite different, the intended
> purpose of the two approaches is also different. That might be a
> reason why there is no consensus here. You are probably asking about
> RE-based sampling on M/T-series or MX. Please clarify if this is
> correct, so that we don't mix these things.

My border routers are a pair of M120s with Adaptive Service PIC-IIs.
My investivation started when I began getting high CPU alerts in the 
message log on the ASPIC-II.  At peak times, the traffic rate was 550-600 
Mb/s out the sp-X/X/X interface and packet rates around 150 kpps.  That's 
when I checked the config and saw that someone had set both routers up for 
1:1 sampling :(

jms