netflow

Can anyone point me to something that will help me set up the netflow
components correctly?
I'm trying to set up a simple simulation using ns3 of 4 nodes. n1 sends to
n2, the router should log details in the IPFIX format and export them out
to n3.
              n3
               |
n1--------router---------n2

I have no idea if I'm setting the system up properly and no idea how to get
netflow components to send the information correctly.
I've taken the example ip routing config file in NS3 and modified it to
bring in the third node and I have an AggregateIPFlow component sitting
between the CheckIPHeader2 and the StaticIPLookup componenets

ch2 :: CheckIPHeader2(...)
 -> af0::AggregateIPFlows()
 -> rt :: StaticIPLookup(....)

For the netflow components I have the following set up

Idle -> NetflowExport(af0, VERSION 10, INTERVAL 1)
    -> NetflowPrint(RECORDS true, VERBOSE true, OUTFILE netflow)
    -> rt;

And this produces nothing for me, if I change VERSION to 9 I get some
output in the netflow file but nothing interesting.
Can someone see what I've missed or show me where I can learn more about
how to set up netflow components and have them send packets from the router
to n3 while the simulation runs?

Cheers,
Anthony