Documentation to integrate FastNetMon with inline jflow using Juniper MX Series routers (MX5, MX10, MX40, MX80, MX104, MX120, MX240, MX480, MX960).

In this example, we use rate=500. It works well for amount of traffic from  100 Mbits/s. But you can increase to rate=1000, depending on your traffic.

For FastNetMon Community you need to change fastnetmon.conf netflow_sampling_ratio with same rate you setup on your MX router.

For FastNetMon Advanced you could change sampling value this way:

Our topology is two MX80 routers, named r1 and r2. From each router connected directly to FastNetMon server.

FastNetMon server has 2 interfaces: – connected to r1 – connected to r2 c R1 has 1 transit connected to ge-1/0/0.0 R2 has 1 transit connected to ge-1/0/0.0

Setting sampling on transit interfaces. Run that on those interfaces on each router.

Check interfaces configuration:

Now add templates configuration on r1 and r2. Take care of flow-active-timeout and flow-inactive-timeout it should be less than average_calculation_time.

You could set new average_calculation_time using configuration option in fastnetmon.conf in FastNetMon Community.

For FastNetMon Advanced you could use command line interface to configure it:

Full configuration:

Now setup ipfix exports:

If you still have inaccurate traffic with Juniper MX, please check our guide about fine tuning for flow tables.