Some folks may have noticed that I'm already listed on the NANOG program to give a talk on "pushback", a scheme for defending against DDoS attacks. Ratul Mahajan, Vern Paxson, Sall Floyd, Scott Shenker, John Ioannidis, and I have nearly finished writing a paper describing the scheme; we hope to make it available on the Web within the next couple of weeks. A note of caution: this is a research paper; it's not something you can turn on on your router today. I'm discussing it at NANOG because we really want input from operators and vendors on how feasible it seems, and on what we've missed. --Steve Bellovin, http://www.research.att.com/~smb