On Mon, Feb 6, 2012 at 8:43 PM, Sven Olaf Kamphuis <sven@cb3rob.net> wrote:
there is a fix for it, it's called "putting a fuckton of ram in -most- routers on the internet" and keeping statistics for each destination ip:destination port:outgoing interface so that none of them individually can (entirely/procentually compared to other traffic) flood the outgoing interface on that router... end result, if enough routers are structured like that, is that ddos attacks will be come completely useless.
There are two obvious problems with your approach. First, adding the policers you suggest, at the scale needed, is a little harder than you imagine. It's not a simple matter of the cost of RAM but also power/heat density per port. Second, if you re-engineer every router on the Internet to prevent an interface from being congested by malicious flow(s) destined for one particular destination IP:port, then DDoS attacks will simply target multiple ports or multiple destination IP addresses that are likely to traverse a link they are able to congest. If you want to dramatically increase the cost of routers in order to solve the problem of DDoS with one deft (and expensive) move, you have to imagine that the people behind DDoS attacks aren't complete idiots, and will actually spend some time thinking about how to defeat your system. -- Jeff S Wheeler <jsw@inconcepts.biz> Sr Network Operator / Innovative Network Concepts