[Ntop] split result by network

[Zorg]

Hello,

I have a network which looks like this :


____
|  1 |
|___|____________
                           |
                           |
____                    |
|  2 |                   |                    ________
|___|____________|ROUTER|__| NTOP |
                           |                   |_place_|
                           |
____                    |
| 3  |                   |
|___|____________|


1 = 192.168.1.0
2 = 192.168.2.0
3 = 192.168.3.0
NTOP = 192.168.4.0


I would like to monitor traffic from place 1, place 2, place 3 to NTOP 
place. Is it possible to split info (as if i had 3 differents 
interfaces), it will be a "logical split".

An other solution is to put nprobe/netflow on each 1, 2, 3, and to 
create 1 interface by nprobe, but i'm afraid that send netflow traffic 
and network traffic on the same link full the link, what do you think 
about it?