I would not post this to nanog unless it was free.
Reactive Network Solutions has made most of FloodGuard's functionality free to download. We are trying to increase awareness of the Internet flooding
problem and at the same time help out the community. If you like this, perhaps
you'll want more from us..
FloodGuard Alert detects and analyzes bandwidth anomalies and provides
useful information to possibly stop the attacks. FloodGuard Alert "learns" normal
traffic over time and has a rich Java GUI with unique traffic monitoring tools.
Our web page has a sign-up form for FloodGuard Alert and more details.