Something like BandwidthD on an embeded pfsense?

I know you can't use packages on an embeded pfSense. So does someone have an idea for a way to monitor traffic per IP as it goes through the firewall?

I have BandwidthD installed right now and it does exactly what I'm looking for. But I am switching to an embeded system so I'm going to loose this.

I do have MRTG running on our network, and that gives me an idea of how much traffic a given piece of hardware is using, but it includes ALL the traffic, including internal only (database, backups, etc.) - I'd really just like to know how much of our internet pipe a given machine is using, which is what BandwidthD gave me.

I've tried running MRTG's cfgmaker against the pfSense box, hoping that maybe traffic counters for all public IPs (or something) would be available, but it only came up with 3 interfaces to monitor.

Sh4

You can use bandwithd in promiscuous mode on another box.