bandwidth usage in bytes on Linux

Hi

I'm looking for a way to create graphs for hobbit on Linux to monitor network bandwidth usage, separately on each interface (eth0,eth1). The provided netstat rrd Network I/O graph measures packets/second but I want bytes/second, which netstat0 (as defined in hobbitgraph.cfg) is supposed to graph but it doesn't since the netstat -s command on my server (RHEL4) doesn't return any byte statistics (only packets).

I suppose I could build something like this (monitoring the /proc/net/dev file) myself if I looked into setting up a custom rrd and so forth, but I'm hoping to save some trouble by asking if someone here has already done this :-D

Help, anyone?