(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@arbor.net>

Avi Freedman CEO, Kentik avi at kentik dot com