This is taken directly from the slashdot website. I thought it was very interesting.

Pushback against DDOS Attacks
Posted by CmdrTaco on Sunday October 27, @08:49AM
from the build-a-better-*******-trap dept.
Huusker writes "Steven Bellovin and others at ATT Research Labs and ICIR have come up with mechanism to stop DDOS attacks. The idea is called Pushback . When the routers get flooded they consult a Unix daemon (/etc/pushbackd) to determine if they are being DDOS'ed. The routers propagate the quench packets back to the sources. The policy and propagation are separate, allowing hardware vendors to concentrate on the quench protocol while the white hats invent ever more clever DDOS detection filters for /etc/pushbackd. The authors of the paper have an initial implementation on FreeBSD."
I would not normally take an article from a different page, but I thought this one should be posted. I searched the forums and didn't see this one yet.