We lack details. As a techy, I want to know the composition of the traffic. Is it blindly overflowing incoming links with junk traffic? Or is it cleverly sending valid DNS requests, overloading the ability of servers to respond, and overflowing outgoing link (as responses are five times or more as big as requests). Such techy details and more make a big difference. Was Dyn the only target? Why were non-Dyn customers effected?
Read the notes by Robert Graham on today’s DDoS attack on Dyn which crippled Internet in United States on Errata Blog.