I'm an avid user of RTG to monitor traffic on switches and routers. I have written a how-to on getting it running on FreeBSD since it requires a little bit of TLC. I run it under DJB's DaemonTools package to help manage getting it running since I was not able to get it to run nicely as a daemon. I'm not a fan of Cacti (I find it too hard to extend past what it is designed to do), so I have ended up running RTG, MRTG, and Cacti to do all of what I want.
http://freebsd.so14k.com/rtg_on_freebsd.shtml
I hope this is useful to others.
http://freebsd.so14k.com/rtg_on_freebsd.shtml
I hope this is useful to others.