Monitor Full Network!

Hi all,

I don't know if anyone can help, but I have to ask ;-)

I'm looking for software, to allow me to monitor my entire network. I have a Router
with a number of servers off it, NT ones and would like to be able to see the network
usage and data follow to all these servers from one machine, maybe even like a real-time graphic.

Ideally I'd like a program like DU Meter (www.dumeter.com) and monitors each ip on my network.

Anyone got any ideas?

Cheers
Paul G