I'm assuming you mean Juniper jflow or sflow, (Netflow is specific to Cisco)
v3.11 (as well as recently released v4.0) , should have the following behavior:
- sflow should work (sflow is by nature sampled)
- sampled jflow should work, but we know that we have some issues with some devices (e.g. JunOS versions) that export flows without specifying that it is being sampled (so NTA processes those flows as unsampled ones=wrong stats).
Whatever your case maybe, if you encounter an issue in this area, we need a pcap, because these are usually NTA "not understanding" how the routers is telling us whether the traffic is sampled or not.
You can contact me directly with pcaps.