NetFlow - path from Routers to Collector

(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.


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 <>

Avi Freedman
CEO, Kentik
avi at kentik dot com

~20% matches our subjective observations, as well.

We're doing our best to increase that number.