[c-nsp] ASR1006 Netflow default sample rate

[Roland Dobbins]

On 10 Jan 2017, at 23:04, Satish Patel wrote:

> How people decide what sample rate is appropriate for them what is the
> criteria to decide?

It's a combination of aggregate bps/pps rates on the interface of the 
router(s) exporting flow telemetry, how flow-generation impacts their 
linecards/platforms, how much DCN/OoB backhaul capacity they have (you 
aren't exporting it in the production data plane of your network, 
right?), and the flows/sec capacity of their collection/analysis system.

~30 records per exported 1500-byte flow telemetry packet is an important 
number to keep in mind.

The idea is to keep the sampling ratio as low (e.g., 1:100 is a *lower* 
sampling ratio than 1:1000) as practicable, given a reasonable balance 
of the factors noted above.

  -----------------------------------
Roland Dobbins <rdobbins at arbor.net>