I just spoke with a customer who was able to get flows to show up in NTA from FProbe on their linux box using two processes (one for in, one for out; designed for high load):
/usr/local/fprobe/sbin/fprobe -x1:2 -ieth1 -B4096 -r2 -q10000 -t10000:10000000 -a 188.8.131.52 184.108.40.206:2055
/usr/local/fprobe/sbin/fprobe -x2:1 -ieth1 -B4096 -r2 -q10000 -t10000:10000000 -a 220.127.116.11 18.104.22.168:2055
22.214.171.124 = Source IP
126.96.36.199 = NetFlow collector IP
2055 = Collector port
Hopefully this helps!