I use this program to measure total bandwidth: http:// 
www.wallwatcher.com/. I also have it setup to report to  
mynetwatchman. However from what I can tell it can not do it on an  
individual internal IP. However, it can keep track on an external IP  
bases.
Jayden
> From: Chuck Mariotti <cmariotti at xunity dot com>
> Date: July 14, 2006 12:50:30 PM GMT-06:00
> To: Chuck Mariotti <cmariotti at xunity dot com>
> Cc: m0n0wall at lists dot m0n0 dot ch
> Subject: RE: [m0n0wall] How to track what's taking up the bandwidth?
>
>
> To clarify, I am looking to find out where my bandwidth is going on  
> EACH
> of my computers behind my firewall.. Specifically, internet traffic.
>
> Doesn't PTRG, etc... just read the stats in Mono and produce a graph?
> What I am looking for is to say, Server #1 is using 10GB/month with  
> 1GB
> going to the internet (monowall), Server #2 is using 5GB with 2GB  
> going
> to the internet (monowall), and Server #3 is using 40GB with 30GB  
> going
> to the internet (monowall)...
>
> This way I can find out which computer is killing me.
>
> Regards,
>
> Chuck