[mrtg] Does MRTG allow checking what IP is using most of bandwidth?

[STF]

Hi there,

     Merry X'mas to everyone first :)

     I have a Fortigate 80C which is a firewall.  I've found that I
could configure it to work with MRTG to get some nice statistics (and
graphs).  Actually, what I want to do is to determine what IP
addresses are using most of Internet bandwidth at any moment (eg
during last 1 minute, last 5 minutes, last 10 minutes, etc).

     I have not really set up MRTG yet.  I have just parsed through
several of your documentations to see if it meets my need but I am not
sure.  I've seen those beautiful graphs in the "Demo", but they are
just showing the traffic through something (a router, maybe?)

     Could someone tell me if showing the biggest network consumers is
possible or not?  What keyword should I use?  Or has anybody ever
configured a Fortigate 80C to do exactly what I'm looking at?

     Thanks a lot in advance. :)