My situation is identical.  In my case, I have a tunnel interface via PPPoE and an ethernet interface connecting to my wireless network.  Since the traffic has to pass through the FreeBSD box, iftop works great on either interface and I can tell who is clogging our DSL connection using it.

Scott

On Fri, Oct 21, 2011 at 8:20 AM, joedson marques <joedson.anid@gmail.com> wrote:
Hello Guys,

I have the scenario following:

One freeBSD that works as router,
so, most of the traffic that pass
through an interface is not connection,
but just packages that  are being routed.

I wanna monitoring all traffic passing
through an interface, no just the traffic
generated by connections.

Is possible make this monitoring without
change the source code of the iftop?

If not, which part of source code should
I change?

Thanks!