On 2013-03-25, at 12:35, Alain Hebert <aheb...@pubnix.net> wrote: > Well, > > Why would you only go after them? > > Easier target to mitigate the problem? > > That might be just me, but I find those peers allowing their > customers to spoof source IP addresses more at fault. > > PS: Some form of adaptive rate limitation works for it btw =D
DNS servers (recursive and authoritative-only) are the low-hanging fruit du jour. I agree that there are many other effective amplifiers, and that even maximum DNS hygiene will not make the wider problem go away. A quick note on your final comment, though: whilst adaptive response rate limiting (so-called RRL) is fast developing into an effective mitigation for reflection attacks against authority-only servers, there is far less experience with traffic patterns or the effects of rate-limiting (using RRL or anything else) on recursive servers. The best advice for operation of recursive servers remains "restrict access to legitimate clients", not "apply rate-limiting". Joe
