[j-nsp] Sampling Traffic --- Urgent

[sthaug at nethelp.no]

> We have tow upstream provider say upstream A and B connected to my end on
> Juniper M10i with JUNOS:9.2. We need to enable sampling or say need to get
> the flow of traffic or collect the data connected to our upstream provider
> Upstream A and B. Doing on practice we have cflowd configured to get the
> traffic sampled, if we enable cflowd for all the interface (Connected to
> Upstream A and B) to get sampled traffice will it be giving the exact
> sampling.If we enabled sampling both interface input and output, how
> sampling sends to the distination server. Please provide us the best
> practice to enable sampling to get the exact sampling of the traffic on our
> network as we have many customers connected behind the router interfaces.

I am not really sure I understand your question. However, I believe
normal practice is to enable sampled netflow on input and output for
the interfaces towards your transit providers, and also for instance
any peering interfaces (towards IXes, private peerings etc). You would
not normally enable netflow on customer interfaces.

I am unclear on what you mean by "exact sampling". By definition, you
are throwing away some information when you are doing sampled netflow.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no