NetFlow - path from Routers to Collector

[freedman at freedman.net (Avi Freedman)]

(Said Roland:)

> Again, to clarify - I count VLANs/VRFs as being sufficiently out-of-band 
> to handle flow telemetry on a reasonable basis without mixing it in with 
> customer traffic.
> 
> That changes the ratio.

<snip>

> I agree with you, Avi, and others that a dedicated OOB network *just for 
> flow telemetry* doesn't make economic sense in most (any?) scenarios.
> 
> What I'm saying is that it oughtn't to be mixed in with customer 
> data-plane traffic.  Ideally, all management-plane traffic would 
> traverse a separate physical infrastructure.  Since we don't live in an 
> ideal world, virtual separation is generally Good Enough.

We see well under 20% doing logical separation but definitely folks
doing it...  For the definition of OOB as "separate routers and 
switches", we don't see anyone really sending flow over that kind
of OOB network.

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

Avi Freedman
CEO, Kentik
avi at kentik dot com